Preamble design aspects for high efficiency wireless local area networks

ABSTRACT

Methods, apparatuses, and computer readable media for resource allocation signaling in a high efficiency wireless local area network (WLAN) are disclosed. A transmitter may identify a first indicator identifying a number of multi-user multiple-input/multiple-output (MU-MIMO) stations associated with a first resource unit (RU) in a first content channel of a transmission frame. The transmitter may generate a first common portion of a WLAN signaling field in the first content channel. The first common portion may include the first indicator. The transmitter may identify a second indicator identifying an absence of MU-MIMO stations associated with a second RU in a second content channel of the transmission frame. The transmitter may generate a second common portion of the WLAN signaling field in the second content channel. The second common portion may include the second indicator. The transmitter may transmit the transmission frame including the WLAN signaling field.

CROSS REFERENCES

The present application for patent claims priority to U.S. ProvisionalPatent Application No. 62/270,562 by Bharadwaj, et al., entitled“Preamble Design Aspects For High Efficiency Wireless Local AreaNetworks,” filed Dec. 21, 2015 and to U.S. Provisional PatentApplication No. 62/299,554 by Bharadwaj, et al., entitled “PreambleDesign Aspects For High Efficiency Wireless Local Area Networks,” filedFeb. 24, 2016 and to U.S. Provisional Patent Application No. 62/328,602by Bharadwaj, et al., entitled “Preamble Design Aspects For HighEfficiency Wireless Local Area Networks,” filed Apr. 27, 2016, and toU.S. Provisional Patent Application No. 62/344,374 by Bharadwaj, et al.,entitled “Preamble Design Aspects For High Efficiency Wireless LocalArea Networks, filed Jun. 1, 2016 and to U.S. Provisional PatentApplication No. 62/365,329 by Bharadwaj, et al., entitled “PreambleDesign Aspects For High Efficiency Wireless Local Area Networks filedJul. 21, 2016 and assigned to the assignee hereof.

BACKGROUND

Field of the Disclosure

The present disclosure, for example, relates to wireless communicationsystems, and more particularly to design aspects of high efficiencywireless local area networks (WLANs).

Description of Related Art

Wireless communications systems are widely deployed to provide varioustypes of communication content such as voice, video, packet data,messaging, broadcast, and so on. These systems may be multiple-accesssystems capable of supporting communication with multiple users bysharing the available system resources (e.g., time, frequency, andpower). A wireless network, for example a Wireless Local Area Network(WLAN), such as a Wi-Fi network (IEEE 802.11) may include an accesspoint (AP) that may communicate with one or more stations (STAs) ormobile devices. The AP may be coupled to a network, such as theInternet, and enable a mobile device to communicate via the network(and/or communicate with other devices coupled to the access point).

A first signaling field and/or a second signaling field of a preambleused for transmitting frames in high efficiency (HE) wireless local areanetworks (WLANs) can be modified to improve performance and efficiencyof HE WLANs.

SUMMARY

Methods, apparatuses, and computer readable media for supportingpreamble design aspects of high efficiency WLANs are disclosed.

A method of wireless communication is described. The method may includeidentifying a first indicator identifying a number of multi-usermultiple input multiple output (MU-MIMO) stations associated with afirst resource unit (RU) in a first content channel of a transmissionframe, generating a first common portion of a WLAN signaling field inthe first content channel of the transmission frame, wherein the firstcommon portion includes the first indicator, identifying a secondindicator identifying an absence of MU-MIMO stations associated with asecond RU in a second content channel of the transmission frame,generating a second common portion of the WLAN signaling field in thesecond content channel of the transmission frame, wherein the secondcommon portion includes the second indicator, and transmitting thetransmission frame that includes the WLAN signaling field.

An apparatus for wireless communication is described. The apparatus mayinclude means for identifying a first indicator identifying a number ofMU-MIMO stations associated with a first RU in a first content channelof a transmission frame, means for generating a first common portion ofa WLAN signaling field in the first content channel of the transmissionframe, wherein the first common portion includes the first indicator,means for identifying a second indicator identifying an absence ofMU-MIMO stations associated with a second RU in a second content channelof the transmission frame, means for generating a second common portionof the WLAN signaling field in the second content channel of thetransmission frame, wherein the second common portion includes thesecond indicator, and means for transmitting the transmission frame thatincludes the WLAN signaling field.

Another apparatus for wireless communication is described. The apparatusmay include a processor, memory in electronic communication with theprocessor, and instructions stored in the memory. The instructions maybe operable to cause the processor to identify a first indicatoridentifying a number of MU-MIMO stations associated with a first RU in afirst content channel of a transmission frame, generate a first commonportion of a WLAN signaling field in the first content channel of thetransmission frame, wherein the first common portion includes the firstindicator, identify a second indicator identifying an absence of MU-MIMOstations associated with a second RU in a second content channel of thetransmission frame, generate a second common portion of the WLANsignaling field in the second content channel of the transmission frame,wherein the second common portion includes the second indicator, andtransmit the transmission frame that includes the WLAN signaling field.

A non-transitory computer readable medium for wireless communication isdescribed. The non-transitory computer-readable medium may includeinstructions operable to cause a processor to identify a first indicatoridentifying a number of MU-MIMO stations associated with a first RU in afirst content channel of a transmission frame, generate a first commonportion of a WLAN signaling field in the first content channel of thetransmission frame, wherein the first common portion includes the firstindicator, identify a second indicator identifying an absence of MU-MIMOstations associated with a second RU in a second content channel of thetransmission frame, generate a second common portion of the WLANsignaling field in the second content channel of the transmission frame,wherein the second common portion includes the second indicator, andtransmit the transmission frame that includes the WLAN signaling field.

In some examples of the method, apparatus, and non-transitorycomputer-readable medium described above, the first common portioncomprises a first common block field and the second common portioncomprises a second common block field of the WLAN signaling field.

In some examples of the method, apparatus, and non-transitorycomputer-readable medium described above, the WLAN signaling fieldcomprises a HE signaling B (HE-SIG-B) field.

A method of wireless communication is described. The method may includereceiving, at a first station, a transmission frame that includes a WLANsignaling field decodable by a plurality of stations, identifying, in astation-specific portion of the WLAN signaling field, an order for aplurality of station-specific information blocks associated with theplurality of stations, and determining a number of spatial streamsallocated to the first station based at least in part on the identifiedorder for the plurality of station-specific information blocks.

An apparatus for wireless communication is described. The apparatus mayinclude means for receiving, at a first station, a transmission framethat includes a WLAN signaling field decodable by a plurality ofstations, means for identifying, in a station-specific portion of theWLAN signaling field, an order for a plurality of station-specificinformation blocks associated with the plurality of stations, and meansfor determining a number of spatial streams allocated to the firststation based at least in part on the identified order for the pluralityof station-specific information blocks.

Another apparatus for wireless communication is described. The apparatusmay include a processor, memory in electronic communication with theprocessor, and instructions stored in the memory. The instructions maybe operable to cause the processor to receive, at a first station, atransmission frame that includes a WLAN signaling field decodable by aplurality of stations, identify, in a station-specific portion of theWLAN signaling field, an order for a plurality of station-specificinformation blocks associated with the plurality of stations, anddetermine a number of spatial streams allocated to the first stationbased at least in part on the identified order for the plurality ofstation-specific information blocks.

A non-transitory computer readable medium for wireless communication isdescribed. The non-transitory computer-readable medium may includeinstructions operable to cause a processor to receive, at a firststation, a transmission frame that includes a WLAN signaling fielddecodable by a plurality of stations, identify, in a station-specificportion of the WLAN signaling field, an order for a plurality ofstation-specific information blocks associated with the plurality ofstations, and determine a number of spatial streams allocated to thefirst station based at least in part on the identified order for theplurality of station-specific information blocks.

Some examples of the method, apparatus, and non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for identifying, in thestation-specific portion, an identifier associated with the firststation, wherein the identified order may be based at least in part onthe identifier associated with the first station.

Some examples of the method, apparatus, and non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for identifying, in a common portion ofthe WLAN signaling field, a number of stations associated with theplurality of stations. Some examples of the method, apparatus, andnon-transitory computer-readable medium described above may furtherinclude processes, features, means, or instructions for identifying, inthe station-specific portion of the WLAN signaling field of thetransmission frame, a total number of spatial streams value associatedwith the plurality of stations, wherein the determined number of spatialstreams allocated to the first station may be based at least in part onthe total number of spatial stream value.

In some examples of the method, apparatus, and non-transitorycomputer-readable medium described above, the common portion comprises acommon block field of the WLAN signaling field.

Some examples of the method, apparatus, and non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for identifying, in a station-specificportion, a spatial configuration field indicating the number of spatialstreams allocated to each station of at least a portion of the pluralityof stations and a total number of spatial streams, wherein thedetermined number of spatial streams allocated to the first station maybe based at least in part on the spatial configuration field.

In some examples of the method, apparatus, and non-transitorycomputer-readable medium described above, the total number of spatialstreams may be associated with a MU-MIMO allocation.

In some examples of the method, apparatus, and non-transitorycomputer-readable medium described above, the WLAN signaling fieldcomprises a HE-SIG-B field.

A method of wireless communication is described. The method may includereceiving a transmission frame associated with a plurality of channels,the transmission frame including a WLAN signaling field, identifying afirst number of stations associated with the WLAN signaling field for afirst channel of the plurality of channels, identifying a second numberof stations associated with the WLAN signaling field for a secondchannel of the plurality of channels, and determining whether a dataportion of the transmission frame contains MU-MIMO content based atleast in part on the identified first number of stations and theidentified second number of stations.

An apparatus for wireless communication is described. The apparatus mayinclude means for receiving a transmission frame associated with aplurality of channels, the transmission frame including a WLAN signalingfield, means for identifying a first number of stations associated withthe WLAN signaling field for a first channel of the plurality ofchannels, means for identifying a second number of stations associatedwith the WLAN signaling field for a second channel of the plurality ofchannels, and means for determining whether a data portion of thetransmission frame contains MU-MIMO content based at least in part onthe identified first number of stations and the identified second numberof stations.

Another apparatus for wireless communication is described. The apparatusmay include a processor, memory in electronic communication with theprocessor, and instructions stored in the memory. The instructions maybe operable to cause the processor to receive a transmission frameassociated with a plurality of channels, the transmission frameincluding a WLAN signaling field, identify a first number of stationsassociated with the WLAN signaling field for a first channel of theplurality of channels, identify a second number of stations associatedwith the WLAN signaling field for a second channel of the plurality ofchannels, and determine whether a data portion of the transmission framecontains MU-MIMO content based at least in part on the identified firstnumber of stations and the identified second number of stations.

A non-transitory computer readable medium for wireless communication isdescribed. The non-transitory computer-readable medium may includeinstructions operable to cause a processor to receive a transmissionframe associated with a plurality of channels, the transmission frameincluding a WLAN signaling field, identify a first number of stationsassociated with the WLAN signaling field for a first channel of theplurality of channels, identify a second number of stations associatedwith the WLAN signaling field for a second channel of the plurality ofchannels, and determine whether a data portion of the transmission framecontains MU-MIMO content based at least in part on the identified firstnumber of stations and the identified second number of stations.

Some examples of the method, apparatus, and non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for determining that a combination ofthe first number of stations and the second number of stations may begreater than one. Some examples of the method, apparatus, andnon-transitory computer-readable medium described above may furtherinclude processes, features, means, or instructions for determining thatthe data portion of the transmission frame contains MU-MIMO content.

Some examples of the method, apparatus, and non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for determining that a combination ofthe first number of stations and the second number of stations may beequal to one. Some examples of the method, apparatus, and non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for determining that the data portionof the transmission frame contains single user (SU) content.

In some examples of the method, apparatus, and non-transitorycomputer-readable medium described above, the WLAN signaling fieldcomprises a HE-SIG-B field.

A method of wireless communication is described. The method may includeidentifying a tone plan to be used for a transmission frame in a WLAN,allocating RUs for a plurality of users for the transmission frame,determining that a RU of the tone plan is unallocated, and generating,for the transmission frame, a station identification in a user specificportion of a WLAN signaling field that indicates that the RU isunallocated.

An apparatus for wireless communication is described. The apparatus mayinclude means for identifying a tone plan to be used for a transmissionframe in a WLAN, means for allocating RUs for a plurality of users forthe transmission frame, means for determining that a RU of the tone planis unallocated, and means for generating, for the transmission frame, astation identification in a user specific portion of a WLAN signalingfield that indicates that the RU is unallocated.

Another apparatus for wireless communication is described. The apparatusmay include a processor, memory in electronic communication with theprocessor, and instructions stored in the memory. The instructions maybe operable to cause the processor to identify a tone plan to be usedfor a transmission frame in a WLAN, allocate RUs for a plurality ofusers for the transmission frame, determine that a RU of the tone planis unallocated, and generate, for the transmission frame, a stationidentification in a user specific portion of a WLAN signaling field thatindicates that the RU is unallocated.

A non-transitory computer readable medium for wireless communication isdescribed. The non-transitory computer-readable medium may includeinstructions operable to cause a processor to identify a tone plan to beused for a transmission frame in a WLAN, allocate RUs for a plurality ofusers for the transmission frame, determine that a RU of the tone planis unallocated, and generate, for the transmission frame, a stationidentification in a user specific portion of a WLAN signaling field thatindicates that the RU is unallocated.

Some examples of the method, apparatus, and non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for generating a predetermined bitsequence for the station identification that indicates that the RU maybe unallocated.

In some examples of the method, apparatus, and non-transitorycomputer-readable medium described above, the WLAN signaling fieldcomprises a HE-SIG-B field.

A method of wireless communication is described. The method may includereceiving a first content channel associated with a transmission frame,the first content channel including a wireless local area network (WLAN)signaling field and identifying, based on at least in part on anindication in the WLAN signaling field, a first number of usersassociated with the first content channel and a second number of usersassociated with a second content channel of the transmission frame.

An apparatus for wireless communication is described. The apparatus mayinclude means for receiving a first content channel associated with atransmission frame, the first content channel including a WLAN signalingfield and means for identifying, based on at least in part on anindication in the WLAN signaling field, a first number of usersassociated with the first content channel and a second number of usersassociated with a second content channel of the transmission frame.

Another apparatus for wireless communication is described. The apparatusmay include a processor, memory in electronic communication with theprocessor, and instructions stored in the memory. The instructions maybe operable to cause the processor to receive a first content channelassociated with a transmission frame, the first content channelincluding a WLAN signaling field and identify, based on at least in parton an indication in the WLAN signaling field, a first number of usersassociated with the first content channel and a second number of usersassociated with a second content channel of the transmission frame.

A non-transitory computer readable medium for wireless communication isdescribed. The non-transitory computer-readable medium may includeinstructions operable to cause a processor to receive a first contentchannel associated with a transmission frame, the first content channelincluding a WLAN signaling field and identify, based on at least in parton an indication in the WLAN signaling field, a first number of usersassociated with the first content channel and a second number of usersassociated with a second content channel of the transmission frame.

Some examples of the method, apparatus, and non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for decoding a common block field ofthe WLAN signaling field for the first channel to identify the firstnumber of users. Some examples of the method, apparatus, andnon-transitory computer-readable medium described above may furtherinclude processes, features, means, or instructions for decoding thecommon block field of the WLAN signaling field for the second channel toidentify the second number of users.

In some examples of the method, apparatus, and non-transitorycomputer-readable medium described above, the common block fieldcomprises RU allocation field.

In some examples of the method, apparatus, and non-transitorycomputer-readable medium described above, the WLAN signaling fieldcomprises a HE-SIG-B field.

A method of wireless communication is described. The method may includeidentifying a first indicator identifying a number of MU-MIMO stationsassociated with a first RU in a first content channel of a transmissionframe, generating a first common portion of a WLAN signaling field inthe first content channel of the transmission frame, wherein the firstcommon portion includes the first indicator, identifying a secondindicator identifying an absence of MU-MIMO stations associated with asecond RU in a second content channel of the transmission frame,generating a second common portion of the WLAN signaling field in thesecond content channel of the transmission frame, wherein the secondcommon portion includes the second indicator, and transmitting thetransmission frame that includes the WLAN signaling field.

An apparatus for wireless communication is described. The apparatus mayinclude means for identifying a first indicator identifying a number ofMU-MIMO stations associated with a first RU in a first content channelof a transmission frame, means for generating a first common portion ofa WLAN signaling field in the first content channel of the transmissionframe, wherein the first common portion includes the first indicator,means for identifying a second indicator identifying an absence ofMU-MIMO stations associated with a second RU in a second content channelof the transmission frame, means for generating a second common portionof the WLAN signaling field in the second content channel of thetransmission frame, wherein the second common portion includes thesecond indicator, and means for transmitting the transmission frame thatincludes the WLAN signaling field.

Another apparatus for wireless communication is described. The apparatusmay include a processor, memory in electronic communication with theprocessor, and instructions stored in the memory. The instructions maybe operable to cause the processor to identify a first indicatoridentifying a number of MU-MIMO stations associated with a first RU in afirst content channel of a transmission frame, generate a first commonportion of a WLAN signaling field in the first content channel of thetransmission frame, wherein the first common portion includes the firstindicator, identify a second indicator identifying an absence of MU-MIMOstations associated with a second RU in a second content channel of thetransmission frame, generate a second common portion of the WLANsignaling field in the second content channel of the transmission frame,wherein the second common portion includes the second indicator, andtransmit the transmission frame that includes the WLAN signaling field.

A non-transitory computer readable medium for wireless communication isdescribed. The non-transitory computer-readable medium may includeinstructions operable to cause a processor to identify a first indicatoridentifying a number of MU-MIMO stations associated with a first RU in afirst content channel of a transmission frame, generate a first commonportion of a WLAN signaling field in the first content channel of thetransmission frame, wherein the first common portion includes the firstindicator, identify a second indicator identifying an absence of MU-MIMOstations associated with a second RU in a second content channel of thetransmission frame, generate a second common portion of the WLANsignaling field in the second content channel of the transmission frame,wherein the second common portion includes the second indicator, andtransmit the transmission frame that includes the WLAN signaling field.

In some examples of the method, apparatus, and non-transitorycomputer-readable medium described above, the first common portioncomprises a first common block field and the second common portioncomprises a second common block field of the WLAN signaling field. Insome examples of the method, apparatus, and non-transitorycomputer-readable medium described above, the WLAN signaling fieldcomprises a HE-SIG-B field.

Some examples of the method, apparatus, and non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for identifying a tone plan for thetransmission frame. Some examples of the method, apparatus, andnon-transitory computer-readable medium described above may furtherinclude processes, features, means, or instructions for allocating RUsfor a plurality of users for the transmission frame. Some examples ofthe method, apparatus, and non-transitory computer-readable mediumdescribed above may further include processes, features, means, orinstructions for determining that a RU of the tone plan may beunallocated. Some examples of the method, apparatus, and non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for generating, for the transmissionframe, a station identification in a user specific portion of a WLANsignaling field that indicates that the RU may be unallocated.

Some examples of the method, apparatus, and non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for generating a predetermined bitsequence for the station identification that indicates that the RU maybe unallocated.

Some examples of the method, apparatus, and non-transitorycomputer-readable medium described above may further include processes,features, means, or instructions for generating a first RU allocationfield in the first common portion of the WLAN signaling field to conveythe indication of the first indicator. Some examples of the method,apparatus, and non-transitory computer-readable medium described abovemay further include processes, features, means, or instructions forgenerating a second RU allocation field in the first common portion ofthe WLAN signaling field to convey the indication of the secondindicator.

A method of wireless communication is described. The method may includereceiving a transmission frame associated with a plurality of channels,the transmission frame including a wireless local area network (WLAN)signaling field, identifying a first number of stations associated withthe WLAN signaling field for a first channel of the plurality ofchannels, identifying a second number of stations associated with theWLAN signaling field for a second channel of the plurality of channels,and determining whether a data portion of the transmission framecontains MU-MIMO content based at least in part on the identified firstnumber of stations and the identified second number of stations.

Another apparatus for wireless communication is described. The apparatusmay include a processor, memory in electronic communication with theprocessor, and instructions stored in the memory. The instructions maybe operable to cause the processor to receive a transmission frameassociated with a plurality of channels, the transmission frameincluding a WLAN signaling field, identify a first number of stationsassociated with the WLAN signaling field for a first channel of theplurality of channels, identify a second number of stations associatedwith the WLAN signaling field for a second channel of the plurality ofchannels, and determine whether a data portion of the transmission framecontains MU-MIMO content based at least in part on the identified firstnumber of stations and the identified second number of stations.

Some examples of the method and apparatus described above may furtherinclude processes, features, means, or instructions for determining thata combination of the first number of stations and the second number ofstations may be greater than one. Some examples of the method andapparatus described above may further include processes, features,means, or instructions for determining that the data portion of thetransmission frame contains MU-MIMO content.

Some examples of the method and apparatus described above may furtherinclude processes, features, means, or instructions for determining thata combination of the first number of stations and the second number ofstations may be equal to one. Some examples of the method and apparatusdescribed above may further include processes, features, means, orinstructions for determining that the data portion of the transmissionframe contains single user (SU) content.

In some examples of the method and apparatus described above, the WLANsignaling field comprises a HE-SIG-B field.

Some examples of the method and apparatus described above may furtherinclude processes, features, means, or instructions for receiving afirst content channel associated with the transmission frame, the firstcontent channel including the WLAN signaling field. Some examples of themethod and apparatus described above may further include processes,features, means, or instructions for identifying, based on at least inpart on an indication in the WLAN signaling field, a first number ofusers associated with the first content channel and a second number ofusers associated with a second content channel of the transmissionframe.

Some examples of the method and apparatus described above may furtherinclude processes, features, means, or instructions for decoding acommon block field of the WLAN signaling field for the first channel toidentify the first number of users. Some examples of the method andapparatus described above may further include processes, features,means, or instructions for decoding the common block field of the WLANsignaling field for the second channel to identify the second number ofusers.

In some examples of the method and apparatus described above, the commonblock field comprises RU allocation field.

The foregoing has outlined rather broadly the features and technicaladvantages of examples according to the disclosure in order that thedetailed description that follows may be better understood. Additionalfeatures and advantages will be described hereinafter. The conceptionand specific examples disclosed may be readily utilized as a basis formodifying or designing other structures for carrying out the samepurposes of the present disclosure. Such equivalent constructions do notdepart from the scope of the appended claims. Characteristics of theconcepts disclosed herein, both their organization and method ofoperation, together with associated advantages will be better understoodfrom the following description when considered in connection with theaccompanying figures. Each of the figures is provided for the purpose ofillustration and description only, and not as a definition of the limitsof the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the nature and advantages of the presentinvention may be realized by reference to the following drawings. In theappended figures, similar components or features may have the samereference label. Further, various components of the same type may bedistinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If only the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label.

FIG. 1 illustrates an example of a wireless communications system thatsupports preamble design aspects for HE WLANs in accordance with variousaspects of the present disclosure;

FIG. 2 shows an example of a WLAN protocol data unit (PDU) (e.g., aphysical layer convergence PDU (PPDU)) preamble design aspects for HEWLANs in accordance with various aspects of the present disclosure;

FIG. 3 illustrates an example of aspects of a WLAN protocol data unitfor preamble design aspects for HE WLANs in accordance with variousaspects of the present disclosure;

FIGS. 4A, 4B, and 4C illustrate examples of aspects of a WLAN protocoldata unit for preamble design aspects for HE WLANs in accordance withvarious aspects of the present disclosure;

FIG. 5 illustrates an example of aspects of a WLAN protocol data unitfor supporting preamble design aspects for HE WLANs in accordance withvarious aspects of the present disclosure;

FIG. 6 illustrates an example of aspects of a portion of a lookup tablefor supporting preamble design aspects for HE WLANs in accordance withvarious aspects of the present disclosure;

FIG. 7 illustrates an example of aspects of a spatial configurationlookup table for supporting preamble design aspects for HE WLANs inaccordance with various aspects of the present disclosure;

FIG. 8 illustrates an example of user specific sub-fields split betweentwo HE-SIG-B content channels, in accordance with various aspects of thepresent disclosure; and

FIGS. 9A through 9C show block diagrams 900-a through 900-c of examplepreamble design aspects for HE WLANs in accordance with various aspectsof the present disclosure;

FIG. 10 illustrates a HE-SIG-B field for a primary HE-SIG-B contentchannel and an HE-SIG-B field for a secondary HE-SIG-B content channelin accordance with various aspects of the present disclosure;

FIGS. 11A and 11B illustrate HE-SIG-B transmission formats that supportpreamble design aspects for HE WLANs in accordance with various aspectsof the present disclosure;

FIGS. 11C and 11D illustrates examples of channels for contiguous andnon-contiguous channel bonding modes, in accordance with various aspectsof the present disclosure;

FIG. 12 illustrates RU allocation table entries for supporting preambledesign aspects for HE WLANs in accordance with various aspects of thepresent disclosure;

FIGS. 13A and 13B show block diagrams of an example device forsupporting preamble design aspects for HE WLANs in accordance withvarious aspects of the present disclosure;

FIGS. 14A through 14D show a first HE-SIG-A field contents for a HE SUPPDU and HE extended range SU PPDU for supporting preamble designaspects for HE WLANs in accordance with various aspects of the presentdisclosure;

FIGS. 15A through 15C show a first HE-SIG-A field contents for a HE MUPPDU for supporting preamble design aspects for HE WLANs in accordancewith various aspects of the present disclosure;

FIGS. 16A through 16B show a first HE-SIG-A field contents for a HEtrigger-based PPDU for supporting preamble design aspects for HE WLANsin accordance with various aspects of the present disclosure;

FIGS. 17A through 17D show a second HE-SIG-A field contents for a HE SUPPDU and HE extended range SU PPDU for supporting preamble designaspects for HE WLANs in accordance with various aspects of the presentdisclosure;

FIGS. 18A through 18C show a second HE-SIG-A field contents for a HE MUPPDU for supporting preamble design aspects for HE WLANs in accordancewith various aspects of the present disclosure;

FIGS. 19A through 19B show a second HE-SIG-A field contents for a HEtrigger-based PPDU for supporting preamble design aspects for HE WLANsin accordance with various aspects of the present disclosure;

FIGS. 20A through 20C show a HE-SIG-A field contents for a HE SU PPDUand HE Extended Range SU PPDU for supporting preamble design aspects forHE WLANs in accordance with various aspects of the present disclosure;

FIGS. 21A through 21C show a HE-SIG-A field contents for a HE MU PPDUfor supporting preamble design aspects for HE WLANs in accordance withvarious aspects of the present disclosure;

FIGS. 22A through 22B show a HE-SIG-A field contents for a HETrigger-based PPDU for supporting preamble design aspects for HE WLANsin accordance with various aspects of the present disclosure; and

FIGS. 23 through 30 illustrate methods for preamble design aspects forHE WLANs in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

In accordance with various aspects of the present disclosure, atransmitter, for example an AP or station, identifies a resource unit(RU) configuration for a wireless local area network (WLAN) data fieldof a single user (SU) transmission frame that has a fixed bandwidth. Thetransmitter generates a RU indicator in a WLAN signaling field of apreamble of the SU transmission frame, the RU indicator identifying a RUsize and a RU location within the WLAN data field. The transmitter thentransmits the SU transmission frame.

In accordance with various aspects of the present disclosure, an APidentifies a first indicator identifying a number of multi-user multipleinput multiple output (MU-MIMO) stations associated with a first RU in afirst content channel of a transmission frame. The AP also generates afirst common portion of a WLAN signaling field in the first contentchannel of the transmission frame, wherein the first common portionincludes the first indicator. The AP identifies a second indicatoridentifying an absence of MU-MIMO stations associated with a second RUin a second content channel of the transmission frame. The AP generatesa second common portion of the WLAN signaling field in the secondcontent channel of the transmission frame, wherein the second commonportion includes the second indicator. The AP then transmits thetransmission frame that includes the WLAN signaling field.

In accordance with various aspects of the present disclosure, a firststation receives a transmission frame that includes a WLAN signalingfield decodable by a plurality of stations. The first stationidentifies, in a station-specific portion of the WLAN signaling field,an order for a plurality of station-specific information blocksassociated with the plurality of stations. The station then determines anumber of spatial streams allocated to the first station based at leastin part on the identified order for the plurality of station-specificinformation blocks.

In accordance with various aspects of the present disclosure, atransmitter, for example an AP or station, receives a transmission frameassociated with a plurality of channels, the transmission frameincluding a WLAN signaling field. The transmitter identifies a firstnumber of stations associated with the WLAN signaling field for a firstchannel of the plurality of channels. The transmitter identifies asecond number of stations associated with the WLAN signaling field for asecond channel of the plurality of channels. The transmitter thendetermines whether a data portion of the transmission frame containsMU-MIMO content based at least in part on the identified first number ofstations and the identified second number of stations.

In accordance with various aspects of the present disclosure, atransmitter, for example an AP or station, generates an indication thata first channel of a plurality of channels associated with atransmission frame has been punctured, the transmission frame includinga WLAN signaling field. The transmitter identifies informationassociated with the WLAN signaling field corresponding to the puncturedfirst channel. The transmitter then transmits the indication that thefirst channel has been punctured and the information associated with theWLAN signaling field in a second channel of the plurality of channels.

These and other aspects of the disclosure are further illustrated by anddescribed with reference to apparatus diagrams, system diagrams, andflowcharts.

FIG. 1 illustrates an example of a wireless communications system 100that supports preamble design aspects for HE WLANs in accordance withvarious aspects of the present disclosure. For simplicity, the wirelesscommunications system 100 is referred to as WLAN 100 in the followingdiscussion.

The WLAN 100 includes an AP 105 and wireless stations (STAs) 110 labeledas STA_1 through STA_7. The STAs 110 can be mobile handsets, tabletcomputers, personal digital assistants (PDAs), other handheld devices,netbooks, notebook computers, tablet computers, laptops, desktopcomputers, display devices (e.g., TVs, computer monitors, etc.),printers, etc. While only one AP 105 is illustrated, the WLAN 100 canhave multiple APs 105. STAs 110, can also be referred to as a mobilestations (MS), mobile devices, access terminals (ATs), user equipment(UEs), subscriber stations (SSs), or subscriber units. The STAs 110associate and communicate with the AP 105 via a communication link 115.Each AP 105 has a coverage area 125 such that STAs 110 within that areaare within range of the AP 105. The STAs 110 are dispersed throughoutthe coverage area 125. Each STA 110 is stationary, mobile, or acombination thereof.

Although not shown in FIG. 1, a STA 110 can be covered by more than oneAP 105 and can therefore associate with multiple APs 105 at differenttimes. A single AP 105 and an associated set of STAs 110 is referred toas a basic service set (BSS). An extended service set (ESS) is a set ofconnected BSSs. A distribution system (DS) (not shown) is used toconnect APs 105 in an extended service set. A coverage area 125 for anAP 105 can be divided into sectors making up only a portion of thecoverage area (not shown). The WLAN 100 includes APs 105 of differenttypes (e.g., metropolitan area, home network, etc.), with varying sizesof coverage areas and overlapping coverage areas for differenttechnologies. Although not shown, other devices can communicate with theAP 105.

While the STAs 110 are capable of communicating with each other throughthe AP 105 using communication links 115, STAs 110 can also communicatedirectly with each other via direct wireless communication links 120.Direct wireless communication links can occur between STAs 110regardless of whether any of the STAs is connected to an AP 105.Examples of direct wireless communication links 120 include Wi-Fi Directconnections, connections established by using a Wi-Fi Tunneled DirectLink Setup (TDLS) link, and other peer-to-peer (P2P) group connections.

The STAs 110 and APs 105 shown in FIG. 1 communicate according to theWLAN radio and baseband protocol including physical (PHY) and mediumaccess control (MAC) layers from IEEE 802.11, and its various versionsincluding, but not limited to, 802.11b, 802.11g, 802.11a, 802.11n,802.11ac, 802.11ad, 802.11ah, 802.11z, 802.11ax, etc.

Transmissions to/from STAs 110 and APs 105 oftentimes include controlinformation within a header that is transmitted prior to datatransmissions. The information provided in a header is used by a deviceto decode the subsequent data. High efficiency (HE) WLAN preambles canbe used to schedule multiple devices, such as STAs 110, for single-usersimultaneous transmission (e.g., single-user orthogonal frequencydivision multiple access (SU-OFDMA)) and/or MU-MIMO transmissions (e.g.,multiple-input/multiple-output MU-MIMO). In one example a HE WLANsignaling field is used to signal a resource allocation pattern tomultiple receiving STAs 110. The HE WLAN signaling field includes acommon user field that is decodable by multiple STAs 110, the commonuser field including a resource allocation field. The resourceallocation field indicates resource unit distributions to the multipleSTAs 110 and indicates which resource units in a resource unitdistribution correspond to MU-MIMO transmissions and which resourceunits correspond to OFDMA single-user transmissions. The HE WLANsignaling field also includes, subsequent to the common user field,dedicated user fields that are assigned to certain STAs 110. The orderin which the dedicated user fields are generated corresponds to theallocated resource units (e.g., the first dedicated user fieldcorresponds to the first allocated resource unit). The HE WLAN signalingfield is transmitted with a WLAN preamble to the multiple STAs 110.

FIG. 2 shows an example of a WLAN protocol data unit (PDU) 200 (e.g., aphysical layer convergence PDU (PPDU)) preamble design aspects for HEWLANs in accordance with various aspects of the present disclosure. WLANPDU 200 illustrates aspects of a transmission between a STA 110 and anAP 105, as described above with reference to FIG. 1.

In this example, the WLAN PDU 200 includes a physical (PHY) layer header205 and a data field 220 (e.g., a MAC PDU (MPDU) or physical layerservice data unit (PSDU)). The PHY layer header 205 includes a legacyWLAN preamble 210 and a high efficiency WLAN preamble 215. The preamblesand data field are transmitted in the following order: legacy WLANpreamble 210, high efficiency WLAN preamble 215, data field 220.

The WLAN PDU 200 is transmitted over a radio frequency spectrum band,which in some examples may include a plurality of sub-bands. In someexamples, the radio frequency spectrum band may have a bandwidth of 80MHz, and each of the sub-bands may have a bandwidth of 20 MHz. Thelegacy WLAN preamble 210 includes legacy short training field (STF)(L-STF) information, legacy long training field (LTF) (L-LTF)information, and legacy signaling (L-SIG) information. When the radiofrequency spectrum band includes multiple sub-bands, the L-STF, L-LTF,and L-SIG information is duplicated and transmitted in each of theplurality of sub-bands. The legacy preamble is used for packetdetection, automatic gain control, channel estimation, etc. The legacypreamble is also used to maintain compatibility with legacy devices.

The high efficiency WLAN preamble 215 includes any of: a repeated legacyWLAN field (e.g., an RL-SIG field), a first WLAN signaling field (e.g.,a first HE WLAN signaling field such as HE-SIG-A), a second WLANsignaling field (e.g., a second HE WLAN signaling field such asHE-SIG-B), a WLAN STF (e.g., a HE WLAN STF), and at least one WLAN LTF(e.g., at least one HE WLAN LTF). The HE WLAN preamble 215 enables an APto simultaneously transmit to multiple stations (e.g., MU-MIMO) and alsoenables an AP to allocate resources to multiple stations foruplink/downlink transmissions (e.g., SU-OFDMA). The HE WLAN preamble 215uses a common signaling field and one or more dedicated (e.g.,station-specific) signaling fields to schedule resources and to indicatethe scheduling to other WLAN devices. A device uses the scheduling todetermine which resource units associated with the frequency spectrumutilized by data field 220 have been allocated to the device forforthcoming communications.

FIG. 3 illustrates an example of aspects of a WLAN PDU 300 for preambledesign aspects for HE WLANs in accordance with various aspects of thepresent disclosure. WLAN PDU 300 illustrates aspects of a transmissionbetween a STA 110 and an AP 105, as described above with reference toFIGS. 1-2. WLAN PDU 300 includes a first WLAN signaling field 305, asecond WLAN signaling field 310, a high efficiency STF 315, a highefficiency LTF 320, and a data field 325. The first WLAN signaling field305 includes an HE-SIG-A 330 that is repeated across multiple subbands.The data field 325 includes data portions 335 that have been allocatedto different devices. For instance, data portion 335-a is allocated to afirst device, data portion 335-b to a second device, data portion 335-cto a first group of devices, and data portion 335-d to a second group ofdevices.

The first WLAN signaling field 305 includes high efficiency WLANsignaling information usable by APs and stations other than a number ofAPs or stations identified to receive or transmit communications in theWLAN PDU 300. The first WLAN signaling field 305 also includesinformation usable by the identified number of APs or stations to decodethe second WLAN signaling field 310. When the radio frequency spectrumband includes a plurality of sub-bands, the information (e.g., HE-SIG-A330-a) included in the first WLAN signaling field 305 is duplicated andtransmitted in each sub-band of the first WLAN signaling field 305,(e.g., HE-SIG-A 330-b to 330-d).

The second WLAN signaling field 310 includes high efficiency WLANsignaling information usable by a number of APs or stations identifiedto transmit or receive communications in the WLAN PDU 300. Morespecifically, the second WLAN signaling field 310 includes informationusable by the number of APs or stations to transmit/encode orreceive/decode data in the data field 220. The second WLAN signalingfield 310 can be encoded separately from the first WLAN signaling field305. The second WLAN signaling field 310 includes a common block field340 that signals information to a group of devices, such as highefficiency STAs within range of an AP, and user blocks 345-a to 345-cthat signal information specific to specific high efficiency STAs. Thecommon block includes a resource allocation field 350 that signals tothe high efficiency device how the data field 325 is partitioned amongstdevices (e.g., partitions the data field into resource units), which ofthe resource units are associated with SU-OFDMA and which are associatedwith MU-MIMO. Furthermore, the order of the user blocks 345 provides alink between the device associated with the user block 345 and theresource unit that has been allocated to the device. As an example, theresource allocation field 350 partitions the data field into nineregions (e.g., 20 MHz data region is partitioned into nine sub-regionsthat each span 26 tones). The STA addressed in the first user blockcorresponds to the first 26 tones, the second STA addressed in thesecond user block corresponds to the next 26 tones, etc. The commonblock may also include other fields, such as a LTF.

FIG. 4A illustrates an example of aspects of a WLAN PDU 400 for preambledesign aspects for HE WLANs in accordance with various aspects of thepresent disclosure. WLAN PDU 400 illustrates aspects of a transmissionbetween a STA 110 and an AP 105, as described above with reference toFIGS. 1-2. WLAN PDU 400 includes a first WLAN signaling field 305-a, ahigh efficiency STF 315-a, a high efficiency LTF 320-a, and a data field325-a. The first WLAN signaling field 305-a includes an HE-SIG-A 330that is repeated across multiple subbands. The data field 325 mayinclude data portions that have been allocated to different devices.

A transmission sent in the HE extended range PPDU format may be sent inenvironments where using a longer range transmission is desirable, e.g.this format may be used for communication with internet of thing (IoT)devices, sensors, etc. A HE extended range PPDU may also have a simplerstructure and be more robust as compared to one or more other HE PPDUformats that may be used for SU transmissions. For example, a HEextended range PPDU format may use a repeated HE-SIG-A field in itspreamble to provide for more robust reception. A HE extended range PPDUmay also be configured to allow for the signaling of smaller resourceunits.

In contrast to a generic SU HE PPDU that may select among severaldifferent bandwidths or have a varying bandwidth (as signaled in the HEpreamble), a HE extended range PPDU for SU transmissions may use a fixedbandwidth, e.g. 20 MHz, that may be smaller than the bandwidth availablefor the generic SU HE PPDU, e.g. where the SU HE PPDU bandwidth is 40MHz, 80 MHz, or 160 MHz. Using a smaller, fixed bandwidth may allow fortransmissions to be sent with a higher power than if the same amount ofpower were spread across a larger bandwidth, e.g. 40 MHz, 80 MHz, or 160MHz, increasing range and robustness for the transmissions. For example,the power for the preamble of the HE extended range PPDU may beincreased or boosted 3 dB above the transmission power of a generic SUHE PPDU. In some case, just the power of the preamble may be boosted bythe transmitter to increase the likelihood of successful reception anddecoding. In other examples, the entire PPDU may be boosted, e.g. by 3dB. In other examples, the HE extended range PPDU may also boost thepower of the transmitted preamble when using a larger bandwidth, such asa 40 MHz, 80 MHz, or 160 MHz bandwidth.

FIG. 4B illustrates an example 401 of aspects of a WLAN PDU for preambledesign aspects for HE WLANs in accordance with various aspects of thepresent disclosure. In the SU HE extended range PPDU in a 20 MHz bandillustrated in FIG. 4B, transmissions to individual users may beallocated to one or more RUs within a tone unit of a PPDU. A size of aRU may be constrained to be one of 106 or 242 tones. In one example of aPPDU, all 242 tones may be allocated to a user for a SU transmission asa single 242-tone RU 435. In another PPDU, 106 tones may be allocated asa first 106-tone RU 430 to a first user for SU transmission, which maybe located in one of two positions. 106 tones may also be allocated as asecond 106-tone RU 430 in this example. Thus, 3 different RU positionsmay be available for RU allocation, which may be indicated by a minimumof 2 bits of an RU allocation field 415.

FIG. 4C illustrates an example 402 of aspects of a WLAN PDU for preambledesign aspects for HE WLANs in accordance with various aspects of thepresent disclosure. In the SU HE extended range PPDU in a 20 MHz bandillustrated in FIG. 4C, transmissions to individual users may beallocated to one or more RUs within a tone unit of a PPDU. A size of aRU may be constrained to be one of 52, 106, or 242 tones. In one exampleof a PPDU, all 242 tones may be allocated to a user for a SUtransmission as a single 242-tone RU 450. In another PPDU, 106 tones maybe allocated as a first 106-tone RU 445 to a first user for SUtransmission, which may be located in one of two positions. 106 tonesmay also be allocated as a second 106-tone RU 445 in this example. Inyet another PPDU, 52 tones may be allocated as a first 52-tone RU 440 toa first user for SU transmission, which may be located in one of fourpositions. 52 tones may also be allocated as a second 52-tone RU 440, asa third 52-tone RU 440, and as a fourth 52-tone RU 440 in this example,for up to 4 different users. Thus, 7 different RU positions may beavailable for RU allocation, which may be indicated by a minimum of 3bits of an RU allocation field 415.

Thus, to maintain simplicity and reduce overhead, the number ofcombinations of RU sizes and locations may be limited to a maximum of 4possibilities (for a 2 bit allocation as described above in reference toFIG. 4B) or a maximum of 8 possibilities (for a 3 bit allocation asdescribed above in reference to FIG. 4C) for the HE extended range PPDU,meaning that 2 or 3 bits in the SIG-A field of the PPDU preamble may beused to identify, for a given RU, which of 3 or 7, respectively,possible RU sizes and locations are allocated. Where the bandwidth isfixed, for example to 20 MHz, additional bits are not needed in theSIG-A field of the PPDU preamble to identify the bandwidth used,simplifying the preamble.

In some examples, the RU allocation field 415 may only be used in anexample where the bandwidth of PPDU is indicated by the BW field 410 tobe 20 MHz. The 2 bits of the BW field 410 may be used to indicate thatthe PPDU uses one of four different bandwidths. Where the BW field 410indicates a bandwidth of 20 MHz (or another predetermined bandwidthaccording to other examples), the recipient of the PPDU may assume thatthe HE-SIG-A field 305-a contains the RU allocation field 415 followingthe BW field 410, and the RU allocation field 415 may be followed by anMCS field 420 and a Nsts field 425, as illustrated in FIG. 4A. Where theBW field 410 indicates a bandwidth other than 20 MHz (or the otherpredetermined bandwidth), for example 40 MHz, 80 MHz, or 160 MHz, thenthe recipient of the PPDU may assume that the HE-SIG-A field 305-acontains MCS field 420 following the BW field 410, and that the RUallocation field 415 has been omitted. Although the BW field 410, RUallocation field 415, MCS field 420, and Nsts field 425 are illustratedas falling one immediately after the other, intermediate fields mayexist, or the fields may be rearranged to occur at differing positions.

In some instances, the HE-SIG-A field 305-a where the BW field 410indicates a higher bandwidth, e.g. 40 MHz, 80 MHz, or 160 MHz, theHE-SIG-A field for the SU HE extended range PPDU may have the sameformat as for a non-extended range format PPDU, e.g. the HE-SIG-A fieldfor the SU HE PPDU. Maintaining a similar format for the HE-SIG-A fieldfor certain bandwidths of the SU extended range HE PPDU as the SU HEPPDU may increase simplicity of implementation.

Where an RU allocation field 415 in the HE-SIG-A field 305-a (e.g. inthe case where BW field 410 indicates a 20 MHz bandwidth), thenadditional bits in the HE-SIG-A field may be needed. For example, thesize of the HE-SIG-A field 305-a may be constrained, such thatintroducing bits in an RU allocation field 415 may push the size of thefield over that constraint. As described above, the size of the RUallocation field 415 may be 2 bits in some examples. In such case, thesize of the MCS field may be limited to 2 bits, for example where thesize of the MCS field 420 in the absence of an RU allocation field 415would otherwise be 4 bits. Thus, the MCS values indicated by the MCSfield 420 may be MCS0, MCS1, MCS2, and MCS3. In an example the four MCSsmay correspond to a BPSK 1/2 MCS, a QPSK 1/2 MCS, a QPSK 3/4 MCS, and a16-QAM 1/2 MCS, respectively.

As also described above, the size of the RU allocation field 415 may be3 bits in some examples. In such case, the size of the MCS field may belimited to 1 bit. Thus, in one example, the MCS values indicated by theMCS field 420 may be MCS0 and MCS1. In an example the two MCSs maycorrespond to a BPSK 1/2 MCS and a QPSK 1/2 MCS, respectively. Thus, 1bit may be used in the SIG-A field of the preamble to identify whether afirst MCS or a second MCS is used to modulate and code the PPDU data;and 2 bits may be used in the SIG-A field of the preamble to identifywhether a first, a second, a third, or a fourth MCS is used to modulateand code the PPDU data. In other examples, the MCS field may be omitted,such that MCS0 is used where the BW is indicated to be 20 MHz.

In other example, the number of spatial streams (Nsts) may also belimited so that the RU allocation field 415 may be used, or to providefurther reserved bits to be used for other purposes. Thus, Nsts may belimited to two options, e.g. Nsts=0 or Nsts=1, and the SIG-A field mayhave a Nsts field 425 that may contain a single bit to indicate thenumber of spatial streams, Nsts. In other examples the Nsts field 425may have 2 bits to indicate up to 4 spatial streams, or 3 bits toindicate up to 8 spatial streams. In other examples, the Nsts field 425may be omitted, such that a single stream is used where the BW isindicated to be 20 MHz.

As described above, limiting the number of bits used for MCS field 420and Nsts field 425 may also decrease the complexity that a receiverneeds to handle and decoding, thus decreasing the power consumption atthe receiver and decreasing the amount of testing that may need to beperformed, even if the extra reserved bits created by limiting the sizeof such fields are not used for implementing other features.

FIG. 5 illustrates an example of aspects of a WLAN PDU 500 forsupporting preamble design aspects for HE WLANs in accordance withvarious aspects of the present disclosure. WLAN PDU 500 illustratesaspects of a transmission between a STA 110 and an AP 105, as describedabove with reference to FIGS. 1-2. WLAN PDU 500 includes an HE-SIG-Bfield 310-a, which is an example of a second WLAN signaling field 310.HE-SIG-B field 310-a includes two content channels 405-a and 405-bincluding control information. In one example, a device decodes bothchannels to acquire all of the content signaled in the HE-SIG-B field310-a. Furthermore, a device that receives a user block within afrequency band associated with a stream 405 also received data withinthe same frequency band. The common portion (e.g. the information incommon block fields 340-a and 340-b) and dedicated portion (e.g., userblocks 345-d and 345-e) for every other 20 MHz channel are signaledtogether. User blocks 345-d and 345-e each include per user informationfor MU-MIMO users in user blocks and per-user information for SU usersin user blocks. The dedicated portion, which includes per userinformation, including user blocks 345-d and 345-e, may be dynamicallyallocated between channels during load balancing.

For example, 8 MU-MIMO users may be allocated RUs in channel 405-a andchannel 405-b. RUs may be allocated by the common portion 340-a of theHE-SIG-B field 310-a to 5 MU-MIMO users of the 8 MU-MIMO users. Thededicated portion 345-d of the HE-SIG-B field 310-a may then provideinformation, once decoded by a station that is one of the 5 MU-MIMOusers, that identifies where data for that station is found in the dataportion associated with the channel 405-a of the transmission frame.Similarly, RUs may be allocated by the common portion 340-b of theHE-SIG-B field 310-a to 5 MU-MIMO users of the 8 MU-MIMO users. Thededicated portion 345-e of the HE-SIG-B field 310-a may then provideinformation, once decoded by a station that is one of the 3 MU-MIMOusers, that identifies where data for that station is found in the dataportion associated with the channel 405-b of the transmission frame(e.g. PPDU).

To perform load balancing, a transmitter, e.g. an AP or station, maysplit up a number of MU-MIMO users in different ways. For WLAN PDU 500,8 MU-MIMO users are split with 5 MU-MIMO users, which are allocated RUsof 484 tones associated with the first channel 405-a, and 3 MU-MIMO,which are allocated RUs of 484 tones associated with the second channel405-b. In other examples, a user may be allocated RUs that are largerthan the maximum RU size for a single channel. For example where themaximum RU size for a channel is 242 tones, an allocated RU for 1 ormore MU-MIMO users may be 484 tones spanning two channels (e.g., two 20MHz channels making a 40 MHz allocation). For these larger allocations,e.g. where the RU size is 484 tones or larger, a number of MU-MIMO usersmay be split between a first channel and a second channel, for examplefrom 1 to 8 MU-MIMO users. However, for purposes of load balancing,where it may be desirable to balance RU allocations between a firstchannel and a second channel, it may assist load balancing to providethe ability to allocate zero or no MU-MIMO users to a channel. Forexample, where a first channel already has a number of blocks allocatedto SU transmissions for a number of users, and a second channel has nosuch blocks allocated to SU transmissions, for purposes of loadbalancing, the transmitter may then allocate zero or no MU-MIMO blocksto the first channel, and each of the remaining MU-MIMO blocks forMU-MIMO users to the second channel.

FIG. 12 illustrates RU allocation table entries 1200 for supportingpreamble design aspects for HE WLANs in accordance with various aspectsof the present disclosure. In some examples for load balancing, areceiving station receive a downlink transmission including multiplechannels, according to preamble design aspects for HE WLANs inaccordance with various aspects of the present disclosure. The downlinktransmission may include WLAN signaling field 310. The signaling fieldmay include a common portion in a first channel, e.g. channel 405-a fora first number of users, and a common portion in a second channel, e.g.channel 405-b for a second number of user. In some examples, thereceiving station may need to successfully decode the common portions ofboth SIG-B content channels to determine the total number of users sothat a total number of user blocks may be determined. So that a stationmay decode one of the channels, but not necessarily the second channel,a total number of users may be indicated in RU allocation table 1200.

RU allocation table 1200 includes a number of entries 1205, an RU size1210, and a user indication 1215. A brief explanation 1220 is alsoincluded in RU allocation table 1200. In this example, the RU size 1210is 484 tones, but additional RU sizes may also be accommodated, forexample 996 tones. In addition, the RU allocation table may haveadditional entries that are not shown in the RU allocation table portionshown in FIG. 12.

In the example illustrated in FIG. 12, 8 entries 1225 may be provided toindicate the number of users where load balancing is not beingperformed. Additional entries 1230 may be added to indicate thedistribution of users between channels for load balancing. For example afirst entry 1230 may indicate that there are no user blocks transmitted.A second entry 1225 indicates a user indication of “1+1” where theprimary channel contains a first user block and the secondary channelcontains a second user block. A third entry 1230 indicates “2+1” wherethat the primary channel contains two user blocks and the secondarychannel contains one user block. And so on to the user indication of“4+4” indicating that the primary channel contains four user blocks andthe secondary channel contains four user blocks.

In other examples, additional combinations may be added to the RUallocation table to provide further load balancing capabilities, e.g.entries 1230 for a “7+1” combination for the primary and secondarychannels, or “2+4” for the primary and secondary channels, and so on. Inother examples, each combination may be included in the RU allocationtable. In addition, the RU allocation table may be needed for larger RUsizes, e.g. 996 tones, 996*2 tones, and so on.

FIG. 6 illustrates an example of aspects of a portion of a lookup table600 for supporting preamble design aspects for HE WLANs in accordancewith various aspects of the present disclosure. Lookup table 600 is aportion of a lookup table, specifically rows that contain RU allocationsof at least 102 tones, that may be used to signal RU allocationsignaling in a common block field of a HE-SIG-B field of a HE PPDU asdescribed above. Lookup table 600 may indicate the location of the SIG-Bdedicated content for large SU allocations, and allows for loadbalancing in the case of large RU sizes, e.g. 484 tones or larger. Toprovide the ability to transmit no or zero MU-MIMO blocks for a RU sizeof 484 tones or larger, a lookup table that indicates a number ofMU-MIMO users associated with a RU may be modified by adding rows to thetable. In particular a row 605 may be added so that, in addition tosignaling that there are 1 through 8 MU-MIMO user blocks transmitted ina particular SIG-B content channel associated with the 484 tone RUallocation, that an indication of an absence of a MU-MIMO user blocktransmitted in the said SIG-B content channel with the 484 toneallocation, i.e. there is no MU-MIMO user block transmitted with the 484tone allocation for that channel. Similarly, a row 610 may be added sothat, in addition to signaling that there are 1 through 8 MU-MIMO userblocks transmitted with a SIG-B content channel with the 996 tone RUallocation, that an indication of an absence of a MU-MIMO user block inthe said SIG-B content channel associated with the 996 tone allocation,i.e. there is no MU-MIMO user block transmitted with the 996 toneallocation for that channel. In other examples, the RU size may vary,such that the additional rows may be used where a RU allocation spanmultiple channels and an indication of zero or an absence of MU-MIMOuser blocks may be indicated for a large RU allocation. It should benoted that where the allocation size is less than 484 tones, accordingto this example, additional rows may not be needed in the lookup table600 because only a single channel will be used, and load balancingbetween 2 or more channels will not take place.

FIG. 7 illustrates an example of aspects of a spatial configurationlookup table 700 for supporting preamble design aspects for HE WLANs inaccordance with various aspects of the present disclosure. A user fieldfor an MU-MIMO allocation, e.g. in a HE-SIG-B field, may include aspatial configuration subfield of 4 bits indicating the number ofspatial streams for each multiplexed STA, the index of the spatialstream, and the total number of spatial streams. Column Nuser indicatesthe number of users; Nuser may be indicated in the common portion (e.g.common block 340) of a HE-SIG-B field. Given Nuser, index of the spatialstream, the total number of spatial stream allocated, and an index ofthe user/station as determined by an order that the user/station appearsin a dedicated portion of a second WLAN signaling field 310 (e.g. aHE-SIG-B field), the number of spatial stream associated with theparticular user/station may be determined. The index of the spatialstream and total number of spatial streams allocated may be communicatedexplicitly. However, the index of the user/station needs to bedetermined based on the order in which it appears in the dedicatedportion, as explained further below. Thus, the index may be implicitlydetermined based on the order, reducing overhead for explicitcommunication of the index.

In a transmission frame, e.g. a HE MU PPDU transmission frame usingMU-MIMO RU allocations, the order of the dedicated portions 345 of asecond WLAN signaling field 310 may be used to determine a number ofspatial streams (Nsts) allocated to a particular user/station that hasreceived the transmission frame. A station may receive a transmissionframe that includes a second WLAN signaling field 310. The station maythen decode the dedicated portions 345 of the second WLAN signalingfield 310 and determine an order for the various stations or users inthe MU-MIMO allocation along with the station that has received thetransmission frame. The order may be predetermined for the station. Forexample, the station (when an AP is the transmitter) may determine thatthe order is based on the identity of the station according to the orderthat it appears in the dedicated portion 345 based on frequency, e.g.proceeding from the lowest subcarrier frequency to the highestsubcarrier frequency (or vice-versa). In one example, the station maydetermine the order of stations appearing in the dedicated portion 345without regard to whether a particular channel is dedicated as a primarychannel (e.g. the primary 20 MHz channel) or a secondary channel (e.g.the secondary 20 MHz channel). In another example, the station maydetermine the order based on frequency, but first for the primarychannel, followed by the secondary channel. For example, the station mayproceed from the lowest subcarrier frequency to the highest subcarrierfrequency (or vice-versa) for the primary channel, followed by thelowest subcarrier frequency to the highest subcarrier frequency (orvice-versa) for the secondary channel. Thus, the station may determinethe order of stations having data communicated in the dedicated portion345.

Having determined the order for each station in the dedicated portion, auser/station may determine its own index based on where the stationappears in the order. That index may then be used in conjunction withspatial configuration lookup table 700 to determine the number ofspatial streams for that station. For example, if Nuser=3, there are atotal number of spatial streams equal to 8, and the station hasdetermined that its index is equal to 2, then the number of spatialstreams associated with the user/station is 3, corresponding to entry705.

In some examples for supporting preamble design aspects for HE WLANs inaccordance with various aspects of the present disclosure, a station maydifferentiate between SU and MU-MIMO allocations. Decoding and combiningboth SIG-B content channels may be used to distinguish between SU andMU-MIMO allocations. Due to load balancing as described above withreference to FIG. 5, Nuser may be one as indicated by a common portion340 in a HE-SIG-B field for a large MU-MIMO allocation. Because thecontent of the SU and MU dedicated portions of a HE-SIG-B field may bedifferent, Nuser indications in a first SIG-B content channel need to becombined with the content in a second SIG-B content channel. Throughcombining, if Nuser for the first content channel plus Nuser for thesecond content channel is greater than 1 (for the same RU), then thecontent is MU-MIMO dedicated content. If Nuser for the first contentchannel plus Nuser for the second content channel is not greater than 1(for the same RU), the content is SU dedicated content.

In other examples for supporting preamble design aspects for HE WLANs inaccordance with various aspects of the present disclosure, HE-SIG-Bcompressed mode 800 may be used. The compressed mode may be used forMU-MIMO utilizing a full bandwidth. In such case, no RU signalinformation is transmitted in a HE_SIG-B filed. Instead, user specificsub-fields are split between the two HE-SIG-B content channels, asillustrated in FIG. 8. In the compressed mode, a number of MU-MIMO usersneed to be indicated. To accomplish this, a field in the SIG-A fieldcorresponding to the number of SIG-B symbols may be re-interpreted orrepurposed, and the number of SIG-B symbols derived from the number ofMU-MIMO users. The number of MU-MIMO users may be computer from thenumber of SIG-B symbols, which could lead to ambiguity in the case wherea high MCS is used. Thus, the number of MU-MIMO users may instead beindicated in a common portion of a HE-SIG-B field. This increasesoverhead because CRC and tail bits are also added to the common portionof the HE-SIG-B field.

In other examples for supporting preamble design aspects for HE WLANs inaccordance with various aspects of the present disclosure, an HE-SIG-Bdesign may use channel bonding. According to an example, SIG-B may notbe transmitted in a channel that has been punctured, for example a 20MHz channel. This may be regardless of whether the preamble in thetransmission frame prior to the SIG-B field has been transmitted or not.The SIG-B transmission format may be determined for secondary 20 MHzchannels that are not transmitted, or other such channels that are nottransmitted. When a second 20 MHz channel is not transmitted, there maybe multiple options to transmit such information.

FIGS. 11A and 11B illustrate HE-SIG-B transmission formats 1100 thatsupport preamble design aspects for HE WLANs in accordance with variousaspects of the present disclosure. In these examples, the 2nd 20 MHzchannel of an 80 MHz bandwidth has been punctured, either in whole or inpart. For example, there may be excessive interference that causes thechannel not to be received a station. In some examples, the SIG-B fieldmay have been punctured, but the SIG-A field or other portions of thepreamble for the channel has not been punctured. A common portion 1105for a primary HE-SIG-B content channel is transmitted in the 1st 20 MHzchannel and the 3rd 20 MHz channel in duplicate. A dedicated portion1115 for the primary HE-SIG-B content channel is also transmitted in the1st 20 MHz channel and the 3rd 20 MHz channel in duplicate. A commonportion 1110 for a secondary HE-SIG-B content channel would otherwise betransmitted in the 2nd 20 MHz channel and the 4th 20 MHz channel induplicate, but as shown, the 2nd 20 MHz channel has been punctured.Likewise, a dedicated portion 1120 for a secondary HE-SIG-B contentchannel would otherwise be transmitted in the 2nd 20 MHz channel and the4th 20 MHz channel in duplicate, but the 2nd 20 MHz channel has beenpunctured. When the secondary 20 MHz channel is punctured, for examplethe 2nd 20 MHz channel, the information that would otherwise becontained in the SIG-B field 310-g may be determined from other channelsor other mechanisms.

In a first example, illustrated in FIG. 11B, information/contents of theSIG-B that was found in the secondary 20 MHz channel may be transmittedon the primary 20 MHz channel. In such case an indication of thepuncturing of the 20 MHz channel may be signaled in the SIG-A field, forexample by including an indicator, which in some examples may be a 1 bitindicator. This increases overhead on the primary channels, e.g. the 1st20 MHz and the 3rd 20 MHz as illustrated in FIG. 11, since the SIG-Bcontent from the secondary channels is transmitted on the primarychannels, in addition to the SIG-B content on the primary channel. Asillustrated for the primary HE-SIG-B content channel for both the 1st 20MHz and the 3rd 20 MHz, common portion 1110 is followed by dedicatedportion 1120 followed by common portion 1105 followed by dedicatedportion 1115. In another example, for the primary HE-SIG-B contentchannel for both the 1st 20 MHz and the 3rd 20 MHz, common portion 1110is followed by common portion 1105 followed by dedicated portion 1120followed by dedicated portion 1115. Whether the common portion of theprimary channel SIG-B content is transmitted first, as illustrated inFIG. 11B, or the secondary channel common portion is transmitted first,or whether another order of the common and dedicated portions may betransmitted, may be predetermined so that upon receiving an indicationin the SIG-A field the receiving station may know the order to decodethe SIG-B field in the primary channel.

As described above, an indicator (e.g., a 1 bit indicator) in the SIG-Afield may be used to indicate puncturing of a 20 MHz channel and thelocation of the SIG-B content channel (e.g., the HE-SIG-B contentchannel in a particular 20 MHz channel of the bandwidth for a PPDU). Insome examples, the BW field of the SIG-A field may include theindication (e.g., the 1 bit indicator). In other examples, the BW field410 described above with reference to FIG. 4, may be used to indicate abandwidth used by a PPDU as well as a location of a SIG-B contentchannel. In some examples, various combinations of PPDU bandwidths andSIG-B content channel locations may be indicated by the BW field 410.

Table 1 below shows example values for a 3-bit BW field in a HE-SIG-Afield of a HE MU PPDU. Where a BW field in a HE-SIG-A field has a valueof 0 or 1, the BW field indicates a PPDU bandwidth of 20 MHz or 40 MHz,respectively. Where a BW field in a HE-SIG-A field has a value of 2, theBW field indicates that the bandwidth for the PPDU carrying the HE-SIG-Afield has a bandwidth of 80 MHz, and that both a first (primary) 20 MHzHE-SIG-B content channel and a second (secondary) 20 MHz HE-SIG-Bcontent channel are present in the primary 40 MHz. Where a BW field in aHE-SIG-A field has a value of 3, the BW field indicates that thebandwidth for the PPDU carrying the HE-SIG-A field has a bandwidth of160 MHz or 80+80 MHz, and that both a first (primary) 20 MHz HE-SIG-Bcontent channel and a second (secondary) 20 MHz HE-SIG-B content channelare in the primary 40 MHz, respectively. Where a BW field in a HE-SIG-Afield has a value of 4, the BW field indicates that the bandwidth forthe PPDU carrying the HE-SIG-A field has a bandwidth of 80 MHz, and thatthe secondary 20 MHz HE-SIG-B content channel is absent from the primary40 MHz, and the counterpart secondary 20 MHz HE-SIG-B content channel isabsent from the secondary 40 MHz. Where a BW field in a HE-SIG-A fieldhas a value of 5, the BW field indicates that the bandwidth for the PPDUcarrying the HE-SIG-A field has a bandwidth of 80 MHz, and that there isa secondary 20 MHz HE-SIG-B content channel absent from the primary 40MHz, and the counterpart secondary 20 MHz HE-SIG-B content channel ispresent in the secondary 40 MHz. Where a BW field in a HE-SIG-A fieldhas a value of 6, the BW field indicates that the bandwidth for the PPDUcarrying the HE-SIG-A field has a bandwidth of 160 MHz or 80+80 MHz, andthat the secondary 20 MHz HE-SIG-B content channel is absent from theprimary 40 MHz, and the counterpart secondary 20 MHz HE-SIG-B contentchannel is absent from the secondary 40 MHz. Where a BW field in aHE-SIG-A field has a value of 7, the BW field indicates that thebandwidth for the PPDU carrying the HE-SIG-A field has a bandwidth of160 MHz or 80+80 MHz, and that there is a secondary 20 MHz HE-SIG-Bcontent channel absent from the primary 40 MHz, and the counterpartsecondary 20 MHz HE-SIG-B content channel is present in the secondary 40MHz.

TABLE 1 Value of BW (3 bit) in HE-SIG-A field of HE MU PPDU ValueDescription 0 20 MHz 1 40 MHz 2 80 MHz with both primary and secondary20 MHz HE-SIG-B content channels present in the primary 40 MHz 3160/80 + 80 with both primary and secondary 20 MHz HE-SIG-B contentchannels present in the primary 40 MHz 4 80 MHz with the secondary 20MHz HE-SIG-B content channel absent from the primary 40 MHz, and itsHE-SIG-B counterpart absent from the secondary 40 MHz 5 80 MHz with thesecondary 20 MHz HE-SIG-B content channel absent from the primary 40MHz, and its HE-SIG-B counterpart present in the secondary 40 MHz 6160/80 + 80 MHz with the secondary 20 MHz HE-SIG-B content channelabsent from the primary 40 MHz, and its HE-SIG-B counterpart absent fromthe secondary 40 MHz 7 160/80 + 80 MHz with the secondary 20 MHzHE-SIG-B content channel absent from the primary 40 MHz, but itsHE-SIG-B counterpart present in the secondary 40 MHz

In some examples, a 2-bit BW field in a SIG-A (e.g., HE-SIG-A) field maybe used to indicate a fewer number of combinations of bandwidth andSIG-B (e.g., HE-SIG-B) content channel, or a 4-bit (or more) BW field ina HE-SIG-A field may be used to indicate a greater number ofcombinations. In other examples, the BW field may be used to indicatedifferent combinations of bandwidth and SIG-B content channel locations.

FIG. 11C illustrates an example of channels 1100-c for a contiguouschannel bonding mode, in accordance with various aspects of the presentdisclosure. Channels 1100-c include a primary 20 MHz channel, asecondary 20 MHz channel, a secondary 40 MHz channel, and a secondary 80MHz channel for a 160 MHz bandwidth. Channels 1100-c include a primary20 MHz channel, a secondary 20 MHz channel, and a secondary 40 MHzchannel for a 80 MHz bandwidth. Channels 1100-c include a primary 20 MHzchannel and a secondary 20 MHz channel for a 40 MHz bandwidth. Channels1100-c may be examples of the corresponding channels described withreference to Table 1.

FIG. 11D illustrates an example of channels 1100-d for a non-contiguouschannel bonding mode, in accordance with various aspects of the presentdisclosure. Channels 1100-d include a primary 20 MHz channel, asecondary 20 MHz channel, a secondary 40 MHz channel, and a secondary 80MHz channel for a 80+80 MHz bandwidth configuration, where the secondary80 MHz channel is not contiguous with the primary 20 MHz channel,secondary 20 MHz channel, and secondary 40 MHz channel. Channels 1100-dmay be examples of the corresponding channels described with referenceto Table 1 for a non-contiguous 80+80 MHz bandwidth, for examplespecifically with reference to BW values 3, 6, and/or 7.

In a second example, for example for an 80 MHz bandwidth as illustratedin FIG. 11A, or a 160 MHz bandwidth containing duplicated SIG-B content,information and/or contents of the SIG-B filed that was found in thepunctured secondary 20 MHz channel corresponding to the 2nd 20 MHz maybe decoded from a 4th 20 MHz channel. In such case an indication of theSIG-B decoding may be signaled in the SIG-A field, for example byincluding an indicator in the SIG-A field. In this example, there may alimitation that the 4th 20 MHz is not also punctured.

In other examples for supporting preamble design aspects for HE WLANs inaccordance with various aspects of the present disclosure, an HE-SIG-Bdesign may be different when other 20 MHz channels are punctured. Insuch case, a common portion of a SIG-B field may be affected since oneor more 20 MHz channels are absent.

In a first example, RU allocation for the punctured 20 MHz channels arenot transmitted. A size of the common portion of the SIG-B field may bemodified depending on the number and location of the punctured channels.In addition, a common portion size may be different between the twoSIG-B content channels. An explicit indication of punctured channels maybe indicated in the SIG-A field.

In a second example, a special or dedicated RU allocation bit sequencemay be used to indicate that a 20 MHz channel is punctured. Theindication may be made by adding an additional entry in a RU allocationtable. A size of the common portion may be unchanged for either contentchannel. According to this example an explicit indication of thepunctured 20 MHz channel may not be needed, though the additional RUallocation bit sequence may result in additional overhead in the commonportion of the SIG-B field.

In these examples, the SIG-B dedicated portion, as opposed to the commonportion, may be relatively unaffected. SIG-B duplicated structure may bemaintained, while the dedicated content for punctured channels are nottransmitted.

In other examples, other 20 MHz channels are punctured. For example, adata portion for a user may be punctured in a secondary channelcorresponding to the 4th 20 MHz. SIG-B information for a 1st user and2nd user may be transmitted in a primary channel, and SIG-B informationfor a 3rd user and 4th user may be transmitted in the secondary channel.If the channel carrying data for the 4th user is punctured, for examplethe 4th 20 MHz as shown in FIG. 11A, then the receiving station mayexpect data for the 4th user because of the presence of an RU allocationin the SIG-B field for the 4th user. Two examples to address thissituation are described below.

In a first example, the RU allocation for the punctured 20 MHz channelmay be not transmitted. The size of the common portion, e.g. commonportion 1105, may then be changed depending on the number and locationof the punctured channels. The common portion size may also be differentbetween the two SIG-B content channels. An explicit indication of whichchannels are punctured may then be communicated in the SIG-A field. Inthis example a number of channels that may be punctured may be limitedby the number of bits allocated in the SIG-A field to communicate which,if any, of the channels are punctured to the receiving station. Forexample, 2 bits in the SIG-A field may allow for the indication of 4possible combinations of punctured channels.

In a second example, an RU allocation bit sequence may be used toindicate that a 20 MHz channel is punctured. An additional entry in anRU allocation table, for example using an otherwise reserved entry inthe RU allocation table, may be used to indicate that a RU is notallocated, e.g. because the 20 MHz channel is punctured. By inserting anadditional entry in the RU allocation table, the size of the commonportion may be unchanged in the content channel. Furthermore, anexplicit indication of the punctured 20 MHz channel may not be needed.According to this second example, the dedicated portion may remainunchanged, while the SIG-B duplicated structure is maintained.

FIGS. 9A through 9C show block diagrams 900-a through 900-c of examplepreamble design aspects for HE WLANs in accordance with various aspectsof the present disclosure.

RU allocation signaling, e.g. using an RU allocation table, may be usedto indicate the allocation plan for each 20 MHz channel of a bandwidth.The size of each allocation and a number of users in each resource unit(RU) may be indicated in the RU allocation table. There may not beadequate numbers of entries available in an RU allocation table toindicate center tones (e.g. the above-described center 26 tones), forexample, because the size of the RU allocation table is limited tominimize an amount of overhead. Such overhead may include the number orsize of dedicated portions or blocks to be sent in the HE-SIG-B field310-b.

An RU allocation table may provide for the allocation plan for channels.Such allocation plans may not provide a provision to account for all thetones in a bandwidth. In some examples, a tone plan may not provide theability to allocate a 26 tone resource unit that falls in the center ofthe tone plan. For example, with reference to FIG. 4B, a 26 tone RU mayfall between the 2 106 tone RUs in the allocation plan 430. Similarly,with reference to FIG. 4C, a 26 tone RU may fall between the 2 106 toneRUs in the allocation plan 445, and/or between the second and third 52tone RUs in the allocation plan 440. In other allocation plans, thetones may not be indicated in the tone plan, but fall between 26 tone,52 tone, or 106 tone RUs elsewhere within an allocation plan. Each suchRU may be referred to herein as a center 26 tone RU.

According to some examples, that a center 26 RU is not allocated may beindicated in a station ID of a user block in the HE-SIG-B field. Acertain sequence for the station ID may be used to indicate that center26 tone RUs are not allocated, e.g. a station ID indicating an RU isunallocated, for example a sequence of 0's or a sequence of 1's for thestation ID used to indicate that a corresponding center 26 tone RU isnot allocated to any station.

In some examples, sending a station ID indicating that an RU isunallocated may require additional overhead. In some examples orimplementations, certain of the RUs are more likely to be unallocatedthan other RUs. For example, the center 26 tone RUs may be the mostlikely to be unallocated. In some examples, the station ID indicatingthat an RU is unallocated may be transmitted if there is room in a padfield 925, but otherwise are not transmitted.

FIG. 9A illustrates the HE-SIG-B field 310-b, including a common block905-a, user blocks for n users 910-a through 910-e, CRC+tail fields915-a through 915-c, an RU allocation for the center 26 tone RU 920-a,and pad bits in a pad field 925-a. In this example, a single channel930-a is shown. According to this example, that an RU is not allocatedmay be indicated in a station ID of a user block 910. A certain sequencefor the station ID may be used to indicate that center 26 tone RUs arenot allocated, for example a sequence of 0's or a sequence of l's. Thesequence of 0's or 1's may also be used to indicate for other of the RUsthat they are unallocated in other examples. Thus, the station ID may beused to indicate that an RU is unallocated. For HE-SIG-B field 310-b, acenter 26 tone RU is not allocated, and the indication is provided byblock 920-a.

FIG. 9B illustrates the HE-SIG-B field 310-c, including a common block905-b, user blocks for n users 910-f through 910-j, CRC+tail fields915-d through 915-f, and pad bits in a pad field 925-b. In this example,a single channel 930-a is shown, where a center 26 tone RU is notallocated. In this example, there is not adequate space available in thepad field 925-b, and as a result, a block including the station ID (e.g.an AID) that indicates that the center 26 RU is unallocated is nottransmitted in the HE-SIG-B field 310-c.

FIG. 9C illustrates the HE-SIG-B field 310-d, including a common block905-c, user blocks for n users 910-k through 910-o, CRC+tail fields915-g through 915-j, and pad bits in a pad field 925-c. In this example,the SIG-B field for a single channel 930-b is shown. In this example,there is adequate space available in the pad 925-b, and as a result, ablocks including the station ID that indicates that center 26 RUs are orare not allocated are transmitted in the HE-SIG-B field 310-c. In oneexample, the SIG-B field may relate to RU allocations for an 80 MHz or160 MHz bandwidth, which there may be five center 26 RUs to beindicated. In this example, pad field 925 provide room for only three ofthe five center 26 RUs to be transmitted, center 26 RU [0] block 925-afor a first RU position, center 26 RU [1] block 925-b for a second RUposition, and center 26 RU [2] block 925-c for a third RU position.Indications that the other two center 26 tone RUs are unallocated arenot sent.

Upon receipt of the HE-SIG-B field 310-d by a station, the station maydecode the center 26 RU blocks 925 and determine that the correspondingcenter 26 RUs are not allocated. The station may also determine that ithas reached the end of the HE-SIG-B field 310-d, and thereby determinethat the remaining two center 26 RUs are also not allocated.

In accordance with preamble design aspects described above, the order ofdedicated (user) content of the user specific subfield of the SIG-Bfield may be ordered according to a number of possible combinations. Inone example, the content may be ordered in the user specific subfieldthe same as the order used in the common portion of the SIG-B field. Insome examples, the content of both the common portion and the userspecific subfield (e.g. the dedicated portion) may be ordered inascending or descending frequency allocated to the user. In otherexamples, the primary channel may be ordered first, followed byascending frequency. In still other examples, the primary channel may beordered first, followed by descending frequency.

FIG. 10 illustrates an HE-SIG-B field 310-f for a primary HE-SIG-Bcontent channel and an HE-SIG-B field 310-e for a second HE-SIG-Bcontent channel in accordance with various aspects of the presentdisclosure. In some examples, the location of the user specific fieldfor the center 26 tone RUs may be at the end of the user block 1020 ofthe SIG-B field, despite the center 26 tone RUs themselves generallyfalling in the middle of a channel. The example shown in FIG. 10includes user specific SIG-B content for the center 26 tone RU SIG-Bcontent for the user specific portions of center 26 tone RUs.Specifically, the primary HE-SIG-B content channel 1005 includes center26 tone RU content for the 1st 20 MHz at block 1065, for the 3rd 20 MHzat block 1070, for the 5th 20 MHz at block 1075, and for the 7th 20 MHzat block 1080, and also includes the center 26 tone RU content for thecenter 26 tones for the primary 80 MHz channel. Specifically, theprimary HE-SIG-B content channel 1010 includes center 26 tone RU contentfor the 2nd 20 MHz at block 1035, for the 4th 20 MHz at block 1040, forthe 6th 20 MHz at block 1045, and for the 8th 20 MHz at block 1050. Forthe example of 160 MHz bandwidth, the HE-SIG-B content channel 1010 alsoincludes the center 26 tone RU content for the center 26 tones for thesecondary 80 MHz channel in block 1055. For the example of 80 MHzbandwidth, the HE-SIG-B content channel 1010 may not include block 1055.

The center 26 tone RU content blocks of the HE-SIG-B field describedabove may indicate that the center 26 tone RUs are allocated. In otherexample fewer or none of the center 26 tone RUs may be allocated. Insuch example, the station ID (AID) described above with reference toFIGS. 9A-9C may be used to indicate that they are not allocated, or theuser specific blocks for the center 26 tone RUs may not be transmitteddue to a lack of padding, also as described with reference to FIGS.9A-9C above.

In some example, overhead may be further reduced by reordering thetransmission order of the center 26 tone RU blocks. For example, if onlythe 7th 20 MHz at block 1080 of the secondary HE-SIG-B content channelwill indicate that a center 26 tone RU is allocated, and the remaining26 tone RUs will be unallocated, then the scheduling that is done by thetransmitting AP may performed such that, if any of the center 26 toneRUs are to be allocated, that they are allocated starting from the 1st20 MHz, not starting with or for only the 7th 20 MHz. Thus, thetransmitting AP may transmit user specific content in the SIG-B fieldfor the allocated center 26 tone RU first, then cease transmitting, andnot transmit additional center 26 tone RUs. Similarly, the station maycease decoding the SIG-B once it encounters an AID value indicating thata center 26 tone RU is not allocated.

In other examples, the order of the center 26 tone RUs may be reorderedaccording to a predetermined order that may be known to both atransmitting AP and a receiving station.

FIGS. 14A through 14D show a first HE-SIG-A field contents 1401-1404 fora HE SU PPDU and HE extended range SU PPDU for supporting preambledesign aspects for HE WLANs in accordance with various aspects of thepresent disclosure. The HE-SIG-A field contents 1401 and HE-SIG-A fieldcontents 1402 together represent a first part of a HE-SIG-A field,HE-SIG-A1, and the HE-SIG-A field contents 1403 and HE-SIG-A fieldcontents 1404 together represent a second part of a HE-SIG-A field,HE-SIG-A2. One or more of HE-SIG-A field contents 1401-1404 may be partof HE WLAN preamble 215 with reference to FIG. 2, and/or HE-SIG-A field305 with reference to FIGS. 3 and 4A. Where HE-SIG-A field contents1401-1404 are implemented for a HE SU PPDU, the HE-SIG-A field contents1401-1404, in aggregate, may be 8 μs. Where HE-SIG-A field contents1401-1404 are implemented for a HE extended range PPDU, the HE-SIG-Afield contents 1401-1404, in aggregate, may be 16 μs. In some examples,the HE-SIG-A field contents 1401-1404 in the HE extended range PPDU maybe 8 μs, but repeated twice making the total length 16 μs.

FIGS. 15A through 15C show a first HE-SIG-A field contents 1501-1503 fora HE MU PPDU for supporting preamble design aspects for HE WLANs inaccordance with various aspects of the present disclosure. The HE-SIG-Afield contents 1501 represents a first part of a HE-SIG-A field,HE-SIG-A1, and the HE-SIG-A field contents 1502 and HE-SIG-A fieldcontents 1503 together represent a second part of a HE-SIG-A field,HE-SIG-A2. One or more of HE-SIG-A field contents 1501-1503 may be partof HE WLAN preamble 215 with reference to FIG. 2, and/or HE-SIG-A field305 with reference to FIGS. 3 and 4A. Where HE-SIG-A field contents1501-1503 are implemented for a HE MU PPDU, the HE-SIG-A field contents1501-1503, in aggregate, may be 8 μs.

FIGS. 16A through 16B show a first HE-SIG-A field contents 1601-1602 fora HE trigger-based PPDU for supporting preamble design aspects for HEWLANs in accordance with various aspects of the present disclosure. TheHE-SIG-A field contents 1601 represents a first part of a HE-SIG-Afield, HE-SIG-A1, and the HE-SIG-A field contents 1602 represents asecond part of a HE-SIG-A field, HE-SIG-A2. One or more of HE-SIG-Afield contents 1601-1602 may be part of HE WLAN preamble 215 withreference to FIG. 2, and/or HE-SIG-A field 305 with reference to FIGS. 3and 4A. Where HE-SIG-A field contents 1601-1602 are implemented for a HEtrigger-based PPDU, the HE-SIG-A field contents 1601-1602, in aggregate,may be 8 μs.

FIGS. 17A through 17D show a second HE-SIG-A field contents 1701-1704for a HE SU PPDU and HE extended range SU PPDU for supporting preambledesign aspects for HE WLANs in accordance with various aspects of thepresent disclosure. The HE-SIG-A field contents 1701 and HE-SIG-A fieldcontents 1702 together represent a first part of a HE-SIG-A field,HE-SIG-A1, and the HE-SIG-A field contents 1703 and HE-SIG-A fieldcontents 1704 together represent a second part of a HE-SIG-A field,HE-SIG-A2. One or more of HE-SIG-A field contents 1701-1704 may be partof HE WLAN preamble 215 with reference to FIG. 2, and/or HE-SIG-A field305 with reference to FIGS. 3 and 4A. Where HE-SIG-A field contents1701-1704 are implemented for a HE SU PPDU, the HE-SIG-A field contents1701-1704, in aggregate, may be 8 μs. Where HE-SIG-A field contents1701-1704 are implemented for a HE extended range PPDU, the HE-SIG-Afield contents 1701-1704, in aggregate, may be 16 μs. In some examples,the HE-SIG-A field contents 1701-1704 in the HE extended range PPDU maybe 8 μs, but repeated twice making the total length 16 μs.

FIGS. 18A through 18C show a second HE-SIG-A field contents 1801-1803for a HE MU PPDU for supporting preamble design aspects for HE WLANs inaccordance with various aspects of the present disclosure. The HE-SIG-Afield contents 1801 represents a first part of a HE-SIG-A field,HE-SIG-A1, and the HE-SIG-A field contents 1802 and HE-SIG-A fieldcontents 1803 together represent a second part of a HE-SIG-A field,HE-SIG-A2. One or more of HE-SIG-A field contents 1801-1803 may be partof HE WLAN preamble 218 with reference to FIG. 2, and/or HE-SIG-A field305 with reference to FIGS. 3 and 4A. Where HE-SIG-A field contents1801-1803 are implemented for a HE MU PPDU, the HE-SIG-A field contents1801-1803, in aggregate, may be 8 μs.

FIGS. 19A through 19B show a second HE-SIG-A field contents 1901-1902for a HE trigger-based PPDU for supporting preamble design aspects forHE WLANs in accordance with various aspects of the present disclosure.The HE-SIG-A field contents 1901 represents a first part of a HE-SIG-Afield, HE-SIG-A1, and the HE-SIG-A field contents 1902 represents asecond part of a HE-SIG-A field, HE-SIG-A2. One or more of HE-SIG-Afield contents 1901-1902 may be part of HE WLAN preamble 215 withreference to FIG. 2, and/or HE-SIG-A field 305 with reference to FIGS. 3and 4A. Where HE-SIG-A field contents 1901-1902 are implemented for a HEtrigger-based PPDU, the HE-SIG-A field contents 1901-1902, in aggregate,may be 8 μs.

FIGS. 20A through 20C show an example of a HE-SIG-A field contents2001-2003 for a HE SU PPDU and HE Extended Range SU PPDU for supportingpreamble design aspects for HE WLANs in accordance with various aspectsof the present disclosure. The HE-SIG-A1 field contents 2001-2002represent a first part of a HE-SIG-A field, HE-SIG-A1, and HE-SIG-A2field contents 2003 represent a second part of the HE-SIG-A field. TheHE-SIG-A field contents 2001-2003 represents aspects of a re-ordering ofvarious HE-SIG-A fields. One or more of HE-SIG-A field contents2001-2003 may be part of HE WLAN preamble 218 with reference to FIG. 2,and/or HE-SIG-A field 305 with reference to FIGS. 3 and 4A.

The HE-SIG-A field contents 2001-2003 provide improved PAPR performancefor HE-SIG-A. In certain aspects, the HE-SIG-A field contents 2001-20003moves the beam change, MCS, DCM, LTE+CP, and Nsts fields to HE-SIG-A1and moves the Txop duration to HE-SIG-A2. For the BSS color description,“0” may indicate public action frames; “63” may indicate IBSS/MBSS/TDLSframes (e.g., when the AP does not provide a color); and “1:62” mayindicate HE BSS color. For the Txop duration description, “127” mayindicate that the Txop duration is not set. For the Doppler description,“1” may indicate that Doppler procedure is used, and “0” may indicateotherwise.

In certain aspects, the format field may differentiate between HE SUPPDU and HE Trigger-based PPDU. Having this field first (e.g., “B0”) maysupport early detection and therefore may be beneficial. Having the BeamChange field as second field may be useful to determine better channelestimation, e.g., the receiver becomes aware of spatial mapping ofpre-HE STF and HE LTF very early in reception. The MCS field in thebeginning helps to determine MCS of the incoming data payload, e.g.,early detect of 1024 QAM MCS enables receiver to enable special powersave mode of reception. The DCM field follows MCS immediately, which mayimpacts the code rate used to calculate data rate for the MCS field.

In some aspects, the BSS Color field supports identifying to which BSSthe packet belongs. The Spatial Reuse field conveys knowledge inconjunction with BSS Color field to help determine if STA can do spatialreuse transmission. In HE SU PPDU and HE Extended Range SU PPDU, the HELTFs may follow the HE_SIG-A2 format. Hence early knowledge of LTF+CPhelps in HE_SIG-A1 to prepare receiver better for channel estimation.

In some aspects, the benefits of HE-SIG-A field contents 2001-2003studied by the PAPR performance of HE-SIG-A for various PPDU formatsconsidering meaningful worst cases. For worst cases (e.g., all 0's andall 1's in HE_SIG A) the sequence of the HE-SIG-A field contents2001-2003 may support PAPR better than PAPR of MCS0 data.

FIGS. 21A through 21C show an example of a HE-SIG-A field contents2101-2103 for a HE MU PPDU for supporting preamble design aspects for HEWLANs in accordance with various aspects of the present disclosure. TheHE-SIG-A field contents 2101-2102 represent a first part of a HE-SIG-Afield, HE-SIG-A1, and the HE-SIG-A field contents 2103 represent asecond part of the HE-SIG-A field, HE-SIG-A2. The HE-SIG-A fieldcontents 2101-2103 represents aspects of a re-ordering of variousHE-SIG-A fields. One or more of HE-SIG-A field contents 2101-2103 may bepart of HE WLAN preamble 218 with reference to FIG. 2, and/or HE-SIG-Afield 305 with reference to FIGS. 3 and 4A.

In certain aspects, the HE-SIG-A field contents 2101-2103 moves the MCS,DCM, LTE+CP, and SIGB # of symbols fields to HE-SIG-A1 and moves theTxop duration to HE-SIG-A2. For the BSS color description, “0” mayindicate public action frames; “63” may indicate IBSS/MBSS/TDLS frames(e.g., when the AP does not provide a Color); and “1:62” may indicate HEBSS color. For the Txop duration description, “127” may indicate thatthe Txop duration is not set. For the Doppler description, “1” mayindicate that Doppler procedure is used, and “0” may indicate otherwise.

FIGS. 22A through 22B show an example of a HE-SIG-A field contents2201-2202 for a HE Trigger-based PPDU for supporting preamble designaspects for HE WLANs in accordance with various aspects of the presentdisclosure. The HE-SIG-A field contents 2201 represents a first part ofa HE-SIG-A field, HE-SIG-A1, and HE-SIG-A field contents 2202 representsa second part of the HE-SIG-A, HE-SIG-A2. The HE-SIG-A field contents2201-2202 represents aspects of a re-ordering of various HE-SIG-Afields. One or more of HE-SIG-A field contents 2201-2202 may be part ofHE WLAN preamble 218 with reference to FIG. 2, and/or HE-SIG-A field 305with reference to FIGS. 3 and 4A.

With reference to FIGS. 14A through 22B, one or more the HE-SIG-A fieldcontents 1401-2202 may include one or more reserved fields. In someexamples, these reserved fields are each set to “1”. Setting thereserved fields to “1”, for example instead of some or all to “0”, mayameliorate issues resulting from large peak-to-average-power (PAPR)ratios that may otherwise be present, and/or assist with binaryconvolutional code (BCC) encoder state setting.

In other examples, the reserved fields, for example bit B0 withreference to HE-SIG-A field contents 1401, 1501, and/or 1601, may beinterpreted differently for a transmitter and a receiver. In oneexample, the reserved field may be set to “1” or “0” by the transmitter,and ignored by the receiver. In a second example, the reserved field maybe set to “1” or “0” by the transmitter, and checked by the receiver forfidelity, such that the receiver may discard the associated PPDU if thefield is set incorrectly. In a third example, the reserved field may beused to indicate a Wi-Fi version associated with the PPDU, such that themeaning of the HE-SIG-A bit fields may be different based on theindicated version of the field. For example, the reserved field, used asa version field, may be set to “0” to indicate IEEE 802.11ax is used,and may be set to “1” to indicate some future version of IEEE 802.11 isused.

In some examples, a bit associated with the “Format” field shown withreference to RE-SIG-A field contents 1401, 1601, 1701, 1901, 2001, 2101,and/or 2201 may be aligned to a B1 bit in a HE SU PPDU and HEtrigger-based PPDU, and used to differentiate between a HE SU PPDU andHE trigger-based PPDU.

In some examples, the “BSS Color” field shown with reference to HE-SIG-Afield contents 1401, 1601, 1701, 1901, 2001, 2101, and/or 2201 maycontain six bits to identify a BSS. In some examples, the six bits ofthe BSS Color filed are each set to “1” to indicate no BSS color.Setting the “BSS Color” field to all “1” to indicate no BSS color ratherthan all “0” to indicate no BSS color can avoid providing a trail of “0”bits.

In other examples, combinations of bit fields for the one or more theHE-SIG-A field contents 1401-2202 may be disallowed. These disallowedcombinations of bit fields may be used to indicate vendor-specificmodes. For example, for a contention period (CP) of 0.4 μs that isindicated to a receiver, a DCM value set to “1” and MCS greater than 4may be a disallowed combination (e.g., because in some circumstances DCMmay be allowed to be applied only for HE-MCSs with indices of 0, 1, 3,or 4). This disallowed combination may still be indicated, but for thetransmitter to indicate a vendor specific mode of operation to thereceiver rather than for the receiver to operate in the otherwisedisallowed combination.

In some examples, and with reference to FIGS. 14A through 22B, the bitfields may be arranged to avoid violating symbol boundaries. Forexample, each of the two reserved bits for a HE SU PPDU and HE extendedrange SU PPDU, “Reserved” field B25 shown in HE-SIG-A field contents1702 and “LDPC extra symbol” field B3 shown in HE-SIG-A field contents1703 may be arranged to be adjacent by swapping “Reserved” field B25shown in HE-SIG-A field contents 1702 with “Coding” field B2 shown inHE-SIG-A field contents 1703. In still other examples, the HEtrigger-based PPDU bit fields may be rearranged such that spatial reuse(SR) and transmit opportunity (TXOP) duration bit fields occurconsecutively. For example, HE-SIG-A field contents 1901-1902 may bearranged as follows: “Format” field B0, “SR” field B1:B16, “TXOP” fieldB17:B23, and “Bandwidth” field B:24:B25 for the HE-SIG-A1 part of theHE-SIG-A field, followed by “BSS Color” field B0:B5, “Reserved” fieldB6:B15, CRC field B16:B19, and “Tail” field B20:B25 for the HE-SIG-A2part of the HE-SIG-A field. Such arrangement may enable the extension ofthe TXOP duration bit field for improved resolution if SR is unused.

FIGS. 13A and 13B show block diagrams of an example device forsupporting preamble design aspects for HE WLANs in accordance withvarious aspects of the present disclosure.

FIG. 13A shows a block diagram 1300-a of an example wireless device 1390that supports preamble design aspects for HE WLANs in accordance withvarious aspects of the present disclosure, and with respect to FIGS.1-12 and 14A-22B. The wireless device 1390, which may be an example of aSTA 110 or an AP 105, includes a resource unit signaling manager 1330, aMU-MIMO load balancer 1335, a spatial stream determiner 1340, a contenttype determiner 1345, and a punctured channel manager 1350. Theprocessor 1305, memory 1310, transceiver(s) 1320, the resource unitsignaling manager 1330, MU-MIMO load balancer 1335, spatial streamdeterminer 1340, content type determiner 1345, and punctured channelmanager 1350 are communicatively coupled with a bus 1355, which enablescommunication between these components. The antenna(s) 1325 arecommunicatively coupled with the transceiver(s) 1320.

The processor 1305 is an intelligent hardware device, such as a centralprocessing unit (CPU), a microcontroller, an application-specificintegrated circuit (ASIC), etc. The processor 1305 processes informationreceived through the transceiver(s) 1320 and information to be sent tothe transceiver(s) 1320 for transmission through the antenna(s) 1325.

The memory 1310 stores computer-readable, computer-executable software(SW) code 1315 containing instructions that, when executed, cause theprocessor 1305 or another one of the components of the wireless device1390 to perform various functions described herein.

The transceiver(s) 1320 communicate bi-directionally with other wirelessdevices, such as APs 105, STAs 110, or other devices. The transceiver(s)1320 include a modem to modulate packets and frames and provide themodulated packets to the antenna(s) 1325 for transmission. The modem isadditionally used to demodulate packets received from the antenna(s)1325.

The resource unit signaling manager 1330, MU-MIMO load balancer 1335,spatial stream determiner 1340, content type determiner 1345, andpunctured channel manager 1350 implement the features described withreference to FIGS. 1-12 and 14A-22B, as further explained below.

The resource unit signaling manager 1330 can identify a resource unit(RU) configuration for a WLAN data field of a SU transmission frame thathas a fixed bandwidth. The resource unit signaling manager 1330 can thengenerate a RU indicator in a WLAN signaling field of a preamble of theSU transmission frame, where the RU indicator identifies a RU size and aRU location within the WLAN data field. The resource unit signalingmanager 1330 can, in some examples together with transceivers 1320and/or antenna(s) 1325, transmit the SU transmission frame.

The MU-MIMO load balancer 1335 can identify a first indicatoridentifying a number of MU-MIMO stations associated with a first RU in afirst content channel of a transmission frame. The MU-MIMO load balancer1335 can also identify a second indicator identifying an absence ofMU-MIMO stations associated with a second RU in a second content channelof the transmission frame. The MU-MIMO load balancer 1335 may thengenerate a first common portion of a WLAN signaling field in the firstcontent channel of the transmission frame, wherein the first commonportion includes the first indicator, and generate a second commonportion of the WLAN signaling field in the second content channel of thetransmission frame, wherein the second common portion includes thesecond indicator. The MU-MIMO load balancer 1335 can, in some examplestogether with transceivers 1320 and/or antenna(s) 1325, transmit the SUtransmission frame that includes the WLAN signaling field.

The spatial stream determiner 1340 can receive a transmission frame thatincludes a WLAN signaling field decodable by a plurality of stations. Insome examples the spatial stream determiner 1340 receives thetransmission frame together with transceivers 1320 and/or antenna(s)1325. The spatial stream determiner 1340 may identify, in astation-specific portion of the WLAN signaling field, an order for aplurality of station-specific information blocks associated with theplurality of stations. The spatial stream determiner 1340 may thendetermine a number of spatial streams allocated to the first stationbased at least in part on the identified order for the plurality ofstation-specific information blocks.

The content type determiner 1345 may receive a transmission frameassociated with a plurality of channels, the transmission frameincluding a WLAN signaling field. In some examples the content typedeterminer 1345 receives the transmission frame together withtransceivers 1320 and/or antenna(s) 1325. The content type determiner1345 can identify a first number of stations associated with the WLANsignaling field for a first channel of the plurality of channels, andidentify a second number of stations associated with the WLAN signalingfield for a second channel of the plurality of channels. The contenttype determiner 1345 may then determine whether a data portion of thetransmission frame contains MU-MIMO content based at least in part onthe identified first number of stations and the identified second numberof stations.

The punctured channel manager 1350 can generate an indication that afirst channel of a plurality of channels associated with a transmissionframe has been punctured, the transmission frame including a WLANsignaling field. The punctured channel manager 1350 can identifyinformation associated with the WLAN signaling field corresponding tothe punctured first channel, then transmit the indication that the firstchannel has been punctured and the information associated with the WLANsignaling field in a second channel of the plurality of channels. Insome examples, the punctured channel manager 1350 operates together withtransceivers 1320 and/or antenna(s) 1325 to transmit the indication andthe information associated with the WLAN signaling field in the secondchannel.

Again, FIG. 13A shows only one possible implementation of a deviceexecuting the features of FIGS. 1-12 and 14A-22B. While the componentsof FIG. 13A are shown as discrete hardware blocks (e.g., ASICs, fieldprogrammable gate arrays (FPGAs), semi-custom integrated circuits, etc.)for purposes of clarity, it will be understood that each of thecomponents may also be implemented by multiple hardware blocks adaptedto execute some or all of the applicable features in hardware.Alternatively, features of two or more of the components of FIG. 13A maybe implemented by a single, consolidated hardware block. For example, asingle transceiver 1320 chip may implement the processor 1305, memory1310, resource unit signaling manager 1330, MU-MIMO load balancer 1335,spatial stream determiner 1340, content type determiner 1345, andpunctured channel manager 1350.

In still other examples, the features of each component may also beimplemented, in whole or in part, with instructions embodied in amemory, formatted to be executed by one or more general orapplication-specific processors. For example, FIG. 13B shows a blockdiagram 1300-b of another example of a wireless device 1390-a in whichthe features of the resource unit signaling manager 1330-a, MU-MIMO loadbalancer 1335-a, spatial stream determiner 1340-a, content typedeterminer 1345-a, and punctured channel manager 1350-a are implementedas computer-readable code stored on memory 1310-a and executed by one ormore processors 1305-a. Other combinations of hardware/software may beused to perform the features of one or more of the components of FIGS.13A-13B.

FIG. 23 shows a flowchart illustrating a method 2300 for preamble designaspects for HE WLANs in accordance with various aspects of the presentdisclosure. The operations of method 2300 may be implemented by awireless device 1390 or its components as described herein, e.g., an AP105 and/or a STA 110. In some examples, an wireless device 1390 mayexecute a set of codes to control the functional elements of the deviceto perform the functions described below. Additionally or alternatively,the wireless device may perform aspects of the functions described belowusing special-purpose hardware.

At block 2305 the wireless device 1310 may identify a first indicatoridentifying a number of MU-MIMO stations associated with a first RU in afirst content channel of a transmission frame. The operations of block2305 may be performed according to the methods described with referenceto FIGS. 1 through 22. In certain examples, aspects of the operations ofblock 2305 may be performed by a component of the wireless device 1390as described with reference to FIG. 13.

At block 2310 the wireless device 1390 may generate a first commonportion of a WLAN signaling field in the first content channel of thetransmission frame, wherein the first common portion includes the firstindicator. The operations of block 2310 may be performed according tothe methods described with reference to FIGS. 1 through 22. In certainexamples, aspects of the operations of block 2310 may be performed by acomponent of the wireless device 1390 as described with reference toFIG. 13.

At block 2315 the wireless device 1390 may identify a second indicatoridentifying an absence of MU-MIMO stations associated with a second RUin a second content channel of the transmission frame. The operations ofblock 2315 may be performed according to the methods described withreference to FIGS. 1 through 22. In certain examples, aspects of theoperations of block 2315 may be performed by a component of the wirelessdevice 1390 as described with reference to FIG. 13.

At block 2320 the wireless device 1390 may generate a second commonportion of the WLAN signaling field in the second content channel of thetransmission frame, wherein the second common portion includes thesecond indicator. The operations of block 2320 may be performedaccording to the methods described with reference to FIGS. 1 through 22.In certain examples, aspects of the operations of block 2320 may beperformed by a component of the wireless device 1390 as described withreference to FIG. 13.

At block 2325 the AP 105 may transmit the transmission frame thatincludes the WLAN signaling field. The operations of block 2325 may beperformed according to the methods described with reference to FIGS. 1through 22. In certain examples, aspects of the operations of block 2325may be performed by a component of the wireless device 1390 as describedwith reference to FIG. 13.

FIG. 24 shows a flowchart illustrating a method 2400 for preamble designaspects for HE WLANs in accordance with various aspects of the presentdisclosure. The operations of method 2400 may be implemented by awireless device 1390 or its components as described herein, e.g., an AP105 and/or a STA 110. In some examples, a wireless device 1390 mayexecute a set of codes to control the functional elements of the deviceto perform the functions described below. Additionally or alternatively,the wireless device 1390 may perform aspects of the functions describedbelow using special-purpose hardware.

At block 2405 the wireless device 1390 may receive, at a first station,a transmission frame that includes a wireless local area network (WLAN)signaling field decodable by a plurality of stations. The operations ofblock 2405 may be performed according to the methods described withreference to FIGS. 1 through 22. In certain examples, aspects of theoperations of block 2405 may be performed by a component of the wirelessdevice 1390 as described with reference to FIG. 13.

At block 2410 the wireless device 1390 may identify, in astation-specific portion of the WLAN signaling field, an order for aplurality of station-specific information blocks associated with theplurality of stations. The operations of block 2410 may be performedaccording to the methods described with reference to FIGS. 1 through 22.In certain examples, aspects of the operations of block 2410 may beperformed by a component of the wireless device 1390 as described withreference to FIG. 13.

At block 2415 the wireless device 1390 may determine a number of spatialstreams allocated to the first station based at least in part on theidentified order for the plurality of station-specific informationblocks. The operations of block 2415 may be performed according to themethods described with reference to FIGS. 1 through 22. In certainexamples, aspects of the operations of block 2415 may be performed by acomponent of the wireless device 1390 as described with reference toFIG. 13.

FIG. 25 shows a flowchart illustrating a method 2500 for Preamble DesignAspects For High Efficiency Wireless Local Area Networks in accordancewith various aspects of the present disclosure. The operations of method2500 may be implemented by a wireless device 1390 or its components asdescribed herein, e.g., an AP 105 and/or a STA 115. In some examples, awireless device 1390 may execute a set of codes to control thefunctional elements of the device to perform the functions describedbelow. Additionally or alternatively, the wireless device 1390 mayperform aspects of the functions described below using special-purposehardware.

At block 2505 the wireless device 1390 may receive a transmission frameassociated with a plurality of channels, the transmission frameincluding a wireless local area network (WLAN) signaling field. Theoperations of block 2505 may be performed according to the methodsdescribed with reference to FIGS. 1 through 22. In certain examples,aspects of the operations of block 2505 may be performed by a componentof the wireless device 1390 as described with reference to FIG. 13.

At block 2510 the wireless device 1390 may identify a first number ofstations associated with the WLAN signaling field for a first channel ofthe plurality of channels. The operations of block 2510 may be performedaccording to the methods described with reference to FIGS. 1 through 22.In certain examples, aspects of the operations of block 2510 may beperformed by a component of the wireless device 1390 as described withreference to FIG. 13.

At block 2515 the wireless device 1390 may identify a second number ofstations associated with the WLAN signaling field for a second channelof the plurality of channels. The operations of block 2515 may beperformed according to the methods described with reference to FIGS. 1through 22. In certain examples, aspects of the operations of block 2515may be performed by a component of the wireless device 1390 as describedwith reference to FIG. 13.

At block 2520 the wireless device 1390 may determine whether a dataportion of the transmission frame contains multi-user multiple inputmultiple output (MU-MIMO) content based at least in part on theidentified first number of stations and the identified second number ofstations. The operations of block 2520 may be performed according to themethods described with reference to FIG. 1 through 22. In certainexamples, aspects of the operations of block 2520 may be performed by acomponent of the wireless device 1390 as described with reference toFIG. 13.

FIG. 26 shows a flowchart illustrating a method 2600 for preamble designaspects for HE WLANs in accordance with various aspects of the presentdisclosure. The operations of method 2600 may be implemented by awireless device 1390 or its components as described herein, e.g., an AP105 and/or a STA 110. In some examples, a wireless device 1390 mayexecute a set of codes to control the functional elements of the deviceto perform the functions described below. Additionally or alternatively,the wireless device 1390 may perform aspects of the functions describedbelow using special-purpose hardware.

At block 2605 the wireless device 1390 may identify a tone plan to beused for a transmission frame in a wireless local area network (WLAN).The operations of block 2605 may be performed according to the methodsdescribed with reference to FIGS. 1 through 22. In certain examples,aspects of the operations of block 2605 may be performed by a componentof the wireless device 1390 as described with reference to FIG. 13.

At block 2610 the wireless device 1390 may allocate resource units (RUs)for a plurality of users for the transmission frame. The operations ofblock 2610 may be performed according to the methods described withreference to FIGS. 1 through 22. In certain examples, aspects of theoperations of block 2610 may be performed by a component of the wirelessdevice 1390 as described with reference to FIG. 13.

At block 2615 the wireless device 1390 may determine that a resourceunit (RU) of the tone plan is unallocated. The operations of block 2615may be performed according to the methods described with reference toFIGS. 1 through 22. In certain examples, aspects of the operations ofblock 2615 may be performed by a component of the wireless device 1390as described with reference to FIG. 13.

At block 2620 the wireless device 1390 may generate, for thetransmission frame, a station identification in a user specific portionof a WLAN signaling field that indicates that the RU is unallocated. Theoperations of block 2620 may be performed according to the methodsdescribed with reference to FIGS. 1 through 22. In certain examples,aspects of the operations of block 2620 may be performed by a componentof the wireless device 1390 as described with reference to FIG. 13.

FIG. 27 shows a flowchart illustrating a method 2700 for preamble designaspects for HE WLANs in accordance with various aspects of the presentdisclosure. The operations of method 2700 may be implemented by awireless device 1390 or its components as described herein, e.g., an AP105 and/or a STA 110. In some examples, a wireless device 1390 mayexecute a set of codes to control the functional elements of the deviceto perform the functions described below. Additionally or alternatively,the wireless device 1390 may perform aspects of the functions describedbelow using special-purpose hardware.

At block 2705 the wireless device 1390 may receive a first contentchannel associated with a transmission frame, the first content channelincluding a wireless local area network (WLAN) signaling field. Theoperations of block 2705 may be performed according to the methodsdescribed with reference to FIGS. 1 through 22. In certain examples,aspects of the operations of block 2705 may be performed by a componentof the wireless device 1390 as described with reference to FIG. 13.

At block 2710 the wireless device 1390 may identify, based on at leastin part on an indication in the WLAN signaling field, a first number ofusers associated with the first content channel and a second number ofusers associated with a second content channel of the transmissionframe. The operations of block 2710 may be performed according to themethods described with reference to FIGS. 1 through 22. In certainexamples, aspects of the operations of block 2710 may be performed by acomponent of the wireless device 1390 as described with reference toFIG. 13.

FIG. 28 shows a flowchart illustrating a method 2800 for preamble designaspects for HE WLANs in accordance with various aspects of the presentdisclosure. The operations of method 2800 may be implemented by awireless device 1390 or its components as described herein, e.g., an AP105 and/or a STA 110. In some examples, a wireless device 1390 mayexecute a set of codes to control the functional elements of the deviceto perform the functions described below. Additionally or alternatively,the wireless device 1390 may perform aspects of the functions describedbelow using special-purpose hardware.

At block 2805 the wireless device 1390 may generate an indication that afirst channel of a plurality of channels associated with a transmissionframe has been punctured, the transmission frame including a wirelesslocal area network (WLAN) signaling field. The operations of block 2805may be performed according to the methods described with reference toFIGS. 1 through 22. In certain examples, aspects of the operations ofblock 2805 may be performed by a component of the wireless device 1390as described with reference to FIG. 13.

At block 2810 the wireless device 1390 may identify informationassociated with the WLAN signaling field corresponding to the puncturedfirst channel. The operations of block 2810 may be performed accordingto the methods described with reference to FIGS. 1 through 22. Incertain examples, aspects of the operations of block 2810 may beperformed by a component of the wireless device 1390 as described withreference to FIG. 13.

At block 2815 the wireless device 1390 may transmit the indication thatthe first channel has been punctured and the information associated withthe WLAN signaling field in a second channel of the plurality ofchannels. The operations of block 2815 may be performed according to themethods described with reference to FIGS. 1 through 22. In certainexamples, aspects of the operations of block 2815 may be performed by acomponent of the wireless device 1390 as described with reference toFIG. 13.

FIG. 29 shows a flowchart illustrating a method 2900 for preamble designaspects for HE WLANs in accordance with various aspects of the presentdisclosure. The operations of method 2900 may be implemented by awireless device 1390 or its components as described herein, e.g., an AP105 and/or STA 110. In some examples, a wireless device 1390 may executea set of codes to control the functional elements of the device toperform the functions described below. Additionally or alternatively,the wireless device 1390 may perform aspects of the functions describedbelow using special-purpose hardware.

At block 2905 the wireless device 1390 may generate an indication that afirst channel of a plurality of channels associated with a transmissionframe has been punctured, the transmission frame including a firstwireless local area network (WLAN) signaling field. The operations ofblock 2905 may be performed according to the methods described withreference to FIGS. 1 through 22. In certain examples, aspects of theoperations of block 2905 may be performed by a component of the wirelessdevice 1390 as described with reference to FIG. 13.

At block 2910 the wireless device 1390 may identify informationassociated with the first WLAN signaling field corresponding to thepunctured first channel. The operations of block 2910 may be performedaccording to the methods described with reference to FIGS. 1 through 22.In certain examples, aspects of the operations of block 2910 may beperformed by a component of the wireless device 1390 as described withreference to FIG. 13.

At block 2915 the wireless device 1390 may transmit the indication thatthe first channel has been punctured in a second WLAN signaling field ofthe transmission frame. The operations of block 2915 may be performedaccording to the methods described with reference to FIGS. 1 through 22.In certain examples, aspects of the operations of block 2915 may beperformed by a component of the wireless device 1390 as described withreference to FIG. 13.

At block 2920 the wireless device 1390 may transmit the informationassociated with the first WLAN signaling field in a second channel ofthe plurality of channels. The operations of block 2920 may be performedaccording to the methods described with reference to FIGS. 1 through 22.In certain examples, aspects of the operations of block 2920 may beperformed by a component of the wireless device 1390 as described withreference to FIG. 13.

FIG. 30 shows a flowchart illustrating a method 3000 for preamble designaspects for HE WLANs in accordance with various aspects of the presentdisclosure. The operations of method 3000 may be implemented by awireless device 1390 or its components as described herein, e.g., an AP105 and/or STA 110. In some examples, a wireless device 1390 may executea set of codes to control the functional elements of the device toperform the functions described below. Additionally or alternatively,the wireless device 1390 may perform aspects of the functions describedbelow using special-purpose hardware.

At block 3005 the wireless device 1390 may identify a bandwidthassociated with a transmission frame. The operations of block 3005 maybe performed according to the methods described with reference to FIGS.1 through 22. In certain examples, aspects of the operations of block3005 may be performed by a component of the wireless device 1390 asdescribed with reference to FIG. 13.

At block 3010 the wireless device 1390 may identify a location for oneor more content channels within the bandwidth. The operations of block3010 may be performed according to the methods described with referenceto FIGS. 1 through 22. In certain examples, aspects of the operations ofblock 3010 may be performed by a component of the wireless device 1390as described with reference to FIG. 13.

At block 3015 the wireless device 1390 may transmit the transmissionframe including a WLAN signaling field indicating both the bandwidth andthe location for the one or more content channels within the bandwidthof the transmission frame. The operations of block 3015 may be performedaccording to the methods described with reference to FIGS. 1 through 22.In certain examples, aspects of the operations of block 3015 may beperformed by a component of the wireless device 1390 as described withreference to FIG. 13.

The detailed description set forth above in connection with the appendeddrawings describes examples and does not represent the only examplesthat may be implemented or that are within the scope of the claims. Theterms “example” and “exemplary,” when used in this description, mean“serving as an example, instance, or illustration,” and not “preferred”or “advantageous over other examples.” The detailed description includesspecific details for the purpose of providing an understanding of thedescribed techniques. These techniques, however, may be practicedwithout these specific details. In some instances, well-known structuresand apparatuses are shown in block diagram form in order to avoidobscuring the concepts of the described examples.

Information and signals may be represented using any of a variety ofdifferent technologies and techniques. For example, data, instructions,commands, information, signals, bits, symbols, and chips that may bereferenced throughout the above description may be represented byvoltages, currents, electromagnetic waves, magnetic fields or particles,optical fields or particles, or any combination thereof.

The various illustrative blocks and components described in connectionwith the disclosure herein may be implemented or performed with ageneral-purpose processor, a digital signal processor (DSP), an ASIC, anFPGA or other programmable logic device, discrete gate or transistorlogic, discrete hardware components, or any combination thereof designedto perform the functions described herein. A general-purpose processormay be a microprocessor, but in the alternative, the processor may beany conventional processor, controller, microcontroller, or statemachine. A processor may also be implemented as a combination ofcomputing devices, e.g., a combination of a DSP and a microprocessor,multiple microprocessors, one or more microprocessors in conjunctionwith a DSP core, or any other such configuration.

The functions described herein may be implemented in hardware, softwareexecuted by a processor, firmware, or any combination thereof. Ifimplemented in software executed by a processor, the functions may bestored on or transmitted over as one or more instructions or code on acomputer-readable medium. Other examples and implementations are withinthe scope and spirit of the disclosure and appended claims. For example,due to the nature of software, functions described above can beimplemented using software executed by a processor, hardware, firmware,hardwiring, or combinations of any of these. Features implementingfunctions may also be physically located at various positions, includingbeing distributed such that portions of functions are implemented atdifferent physical locations. As used herein, including in the claims,the term “and/or,” when used in a list of two or more items, means thatany one of the listed items can be employed by itself, or anycombination of two or more of the listed items can be employed. Forexample, if a composition is described as containing components A, B,and/or C, the composition can contain A alone; B alone; C alone; A and Bin combination; A and C in combination; B and C in combination; or A, B,and C in combination. Also, as used herein, including in the claims,“or” as used in a list of items (for example, a list of items prefacedby a phrase such as “at least one of” or “one or more of”) indicates adisjunctive list such that, for example, a list of “at least one of A,B, or C” means A or B or C or AB or AC or BC or ABC (i.e., A and B andC).

Computer-readable media includes both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. A storage medium may be anyavailable medium that can be accessed by a general purpose or specialpurpose computer. By way of example, and not limitation,computer-readable media can comprise RAM, ROM, EEPROM, flash memory,CD-ROM or other optical disk storage, magnetic disk storage or othermagnetic storage devices, or any other medium that can be used to carryor store desired program code means in the form of instructions or datastructures and that can be accessed by a general-purpose orspecial-purpose computer, or a general-purpose or special-purposeprocessor. Also, any connection is properly termed a computer-readablemedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition of medium.Disk and disc, as used herein, include compact disc (CD), laser disc,optical disc, digital versatile disc (DVD), floppy disk and Blu-ray discwhere disks usually reproduce data magnetically, while discs reproducedata optically with lasers. Combinations of the above are also includedwithin the scope of computer-readable media.

The previous description of the disclosure is provided to enable aperson skilled in the art to make or use the disclosure. Variousmodifications to the disclosure will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other variations without departing from the scope of thedisclosure. Thus, the disclosure is not to be limited to the examplesand designs described herein but is to be accorded the broadest scopeconsistent with the principles and novel features disclosed herein.

What is claimed is:
 1. A method for wireless communication, comprising:identifying a first indicator identifying a number of multi-usermultiple input multiple output (MU-MIMO) stations associated with afirst resource unit (RU) in a first content channel of a transmissionframe; generating a first common portion of a wireless local areanetwork (WLAN) signaling field in the first content channel of thetransmission frame, wherein the first common portion includes the firstindicator; identifying a second indicator identifying an absence ofMU-MIMO stations associated with a second RU in a second content channelof the transmission frame; generating a second common portion of theWLAN signaling field in the second content channel of the transmissionframe, wherein the second common portion includes the second indicator;and transmitting the transmission frame that includes the WLAN signalingfield.
 2. The method of claim 1, wherein: the first common portioncomprises a first common block field and the second common portioncomprises a second common block field of the WLAN signaling field. 3.The method of claim 1, wherein: the WLAN signaling field comprises ahigh efficiency (HE) signaling B (HE-SIG-B) field.
 4. The method ofclaim 1, further comprising: identifying a tone plan for thetransmission frame; allocating RUs for a plurality of users for thetransmission frame; determining that a RU of the tone plan isunallocated; and generating, for the transmission frame, a stationidentification in a user specific portion of the WLAN signaling fieldthat indicates that the RU is unallocated.
 5. The method of claim 4,further comprising: generating a predetermined bit sequence for thestation identification that indicates that the RU is unallocated.
 6. Themethod of claim 1, further comprising: generating a first RU allocationfield in the first common portion of the WLAN signaling field to conveythe indication of the first indicator; and generating a second RUallocation field in the first common portion of the WLAN signaling fieldto convey the indication of the second indicator.
 7. A method forwireless communication, comprising: receiving a transmission frameassociated with a plurality of channels, the transmission frameincluding a wireless local area network (WLAN) signaling field;identifying a first number of stations associated with the WLANsignaling field for a first channel of the plurality of channels;identifying a second number of stations associated with the WLANsignaling field for a second channel of the plurality of channels; anddetermining whether a data portion of the transmission frame containsmulti-user multiple input multiple output (MU-MIMO) content based atleast in part on the identified first number of stations and theidentified second number of stations.
 8. The method of claim 7, furthercomprising: determining that a combination of the first number ofstations and the second number of stations is greater than one; anddetermining that the data portion of the transmission frame containsMU-MIMO content.
 9. The method of claim 7, further comprising:determining that a combination of the first number of stations and thesecond number of stations is equal to one; and determining that the dataportion of the transmission frame contains single user (SU) content. 10.The method of claim 7, wherein: the WLAN signaling field comprises ahigh efficiency (HE) signaling B (HE-SIG-B) field.
 11. The method ofclaim 7, further comprising: receiving a first content channelassociated with the transmission frame, the first content channelincluding the WLAN signaling field; and identifying, based on at leastin part on an indication in the WLAN signaling field, a first number ofusers associated with the first content channel and a second number ofusers associated with a second content channel of the transmissionframe.
 12. The method of claim 11, further comprising: decoding a commonblock field of the WLAN signaling field for the first channel toidentify the first number of users; and decoding the common block fieldof the WLAN signaling field for the second channel to identify thesecond number of users.
 13. The method of claim 11, wherein: the commonblock field comprises resource unit (RU) allocation field.
 14. Anapparatus for wireless communication, comprising: a memory; and aprocessor coupled with the memory and configured to: identify a firstindicator identifying a number of multi-user multiple input multipleoutput (MU-MIMO) stations associated with a first resource unit (RU) ina first content channel of a transmission frame; generate a first commonportion of a wireless local area network (WLAN) signaling field in thefirst content channel of the transmission frame, wherein the firstcommon portion includes the first indicator; identify a second indicatoridentifying an absence of MU-MIMO stations associated with a second RUin a second content channel of the transmission frame; generate a secondcommon portion of the WLAN signaling field in the second content channelof the transmission frame, wherein the second common portion includesthe second indicator; and transmit the transmission frame that includesthe WLAN signaling field.
 15. The apparatus of claim 14, wherein: thefirst common portion comprises a first common block field and the secondcommon portion comprises a second common block field of the WLANsignaling field.
 16. The apparatus of claim 14, wherein: the WLANsignaling field comprises a high efficiency (HE) signaling B (HE-SIG-B)field.
 17. The apparatus of claim 14, wherein the processor and memoryare further configured to: identify a tone plan for the transmissionframe; allocate RUs for a plurality of users for the transmission frame;determine that a RU of the tone plan is unallocated; and generate, forthe transmission frame, a station identification in a user specificportion of the WLAN signaling field that indicates that the RU isunallocated.
 18. The apparatus of claim 17, wherein the processor andmemory are further configured to: generate a predetermined bit sequencefor the station identification that indicates that the RU isunallocated.
 19. The apparatus of claim 14, wherein the processor andmemory are further configured to: generate a first RU allocation fieldin the first common portion of the WLAN signaling field to convey theindication of the first indicator; and generate a second RU allocationfield in the first common portion of the WLAN signaling field to conveythe indication of the second indicator.
 20. An apparatus for wirelesscommunication, comprising: a memory; and a processor coupled with thememory and configured to: receive a transmission frame associated with aplurality of channels, the transmission frame including a wireless localarea network (WLAN) signaling field; identify a first number of stationsassociated with the WLAN signaling field for a first channel of theplurality of channels; identify a second number of stations associatedwith the WLAN signaling field for a second channel of the plurality ofchannels; and determine whether a data portion of the transmission framecontains multi-user multiple input multiple output (MU-MIMO) contentbased at least in part on the identified first number of stations andthe identified second number of stations.
 21. The apparatus of claim 20,wherein the processor and memory are further configured to: determinethat a combination of the first number of stations and the second numberof stations is greater than one; and determine that the data portion ofthe transmission frame contains MU-MIMO content.
 22. The apparatus ofclaim 20, wherein the processor and memory are further configured to:determine that a combination of the first number of stations and thesecond number of stations is equal to one; and determine that the dataportion of the transmission frame contains single user (SU) content. 23.The apparatus of claim 20, wherein: the WLAN signaling field comprises ahigh efficiency (HE) signaling B (HE-SIG-B) field.
 24. The apparatus ofclaim 20, wherein the processor and memory are further configured to:receive a first content channel associated with the transmission frame,the first content channel including the WLAN signaling field; andidentify, based on at least in part on an indication in the WLANsignaling field, a first number of users associated with the firstcontent channel and a second number of users associated with a secondcontent channel of the transmission frame.
 25. The apparatus of claim24, wherein the processor and memory are further configured to: decode acommon block field of the WLAN signaling field for the first channel toidentify the first number of users; and decode the common block field ofthe WLAN signaling field for the second channel to identify the secondnumber of users.
 26. The apparatus of claim 24, wherein: the commonblock field comprises resource unit (RU) allocation field.